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How can I emulate the effect of the C function sprintf_s in C#?

I am trying to take some old code written by my predecessor in C and migrate it to C#. I have tried using the P/invoke way but running into issues with sprint_s. Any recommendation on how to fix this or maybe write it using C#'s SerialPort class?
[StructLayout(LayoutKind.Sequential)]
internal struct Dcb
{
internal uint DCBLength;
internal uint BaudRate;
private BitVector32 Flags;
private ushort wReserved; // not currently used
internal ushort XonLim; // transmit XON threshold
internal ushort XoffLim; // transmit XOFF threshold
internal byte ByteSize;
internal Parity Parity;
internal StopBits StopBits;
internal sbyte XonChar; // Tx and Rx XON character
internal sbyte XoffChar; // Tx and Rx XOFF character
internal sbyte ErrorChar; // error replacement character
internal sbyte EofChar; // end of input character
internal sbyte EvtChar; // received event character
private ushort wReserved1; // reserved; do not use
private static readonly int fBinary;
private static readonly int fParity;
private static readonly int fOutxCtsFlow;
private static readonly int fOutxDsrFlow;
private static readonly BitVector32.Section fDtrControl;
private static readonly int fDsrSensitivity;
private static readonly int fTXContinueOnXoff;
private static readonly int fOutX;
private static readonly int fInX;
private static readonly int fErrorChar;
private static readonly int fNull;
private static readonly BitVector32.Section fRtsControl;
private static readonly int fAbortOnError;
static Dcb()
{
// Create Boolean Mask
int previousMask;
fBinary = BitVector32.CreateMask();
fParity = BitVector32.CreateMask(fBinary);
fOutxCtsFlow = BitVector32.CreateMask(fParity);
fOutxDsrFlow = BitVector32.CreateMask(fOutxCtsFlow);
previousMask = BitVector32.CreateMask(fOutxDsrFlow);
previousMask = BitVector32.CreateMask(previousMask);
fDsrSensitivity = BitVector32.CreateMask(previousMask);
fTXContinueOnXoff = BitVector32.CreateMask(fDsrSensitivity);
fOutX = BitVector32.CreateMask(fTXContinueOnXoff);
fInX = BitVector32.CreateMask(fOutX);
fErrorChar = BitVector32.CreateMask(fInX);
fNull = BitVector32.CreateMask(fErrorChar);
previousMask = BitVector32.CreateMask(fNull);
previousMask = BitVector32.CreateMask(previousMask);
fAbortOnError = BitVector32.CreateMask(previousMask);
// Create section Mask
BitVector32.Section previousSection;
previousSection = BitVector32.CreateSection(1);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
fDtrControl = BitVector32.CreateSection(2, previousSection);
previousSection = BitVector32.CreateSection(1, fDtrControl);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
fRtsControl = BitVector32.CreateSection(3, previousSection);
previousSection = BitVector32.CreateSection(1, fRtsControl);
}
public bool Binary
{
get { return Flags[fBinary]; }
set { Flags[fBinary] = value; }
}
public bool CheckParity
{
get { return Flags[fParity]; }
set { Flags[fParity] = value; }
}
public bool OutxCtsFlow
{
get { return Flags[fOutxCtsFlow]; }
set { Flags[fOutxCtsFlow] = value; }
}
public bool OutxDsrFlow
{
get { return Flags[fOutxDsrFlow]; }
set { Flags[fOutxDsrFlow] = value; }
}
public DtrControl DtrControl
{
get { return (DtrControl)Flags[fDtrControl]; }
set { Flags[fDtrControl] = (int)value; }
}
public bool DsrSensitivity
{
get { return Flags[fDsrSensitivity]; }
set { Flags[fDsrSensitivity] = value; }
}
public bool TxContinueOnXoff
{
get { return Flags[fTXContinueOnXoff]; }
set { Flags[fTXContinueOnXoff] = value; }
}
public bool OutX
{
get { return Flags[fOutX]; }
set { Flags[fOutX] = value; }
}
public bool InX
{
get { return Flags[fInX]; }
set { Flags[fInX] = value; }
}
public bool ReplaceErrorChar
{
get { return Flags[fErrorChar]; }
set { Flags[fErrorChar] = value; }
}
public bool Null
{
get { return Flags[fNull]; }
set { Flags[fNull] = value; }
}
public RtsControl RtsControl
{
get { return (RtsControl)Flags[fRtsControl]; }
set { Flags[fRtsControl] = (int)value; }
}
public bool AbortOnError
{
get { return Flags[fAbortOnError]; }
set { Flags[fAbortOnError] = value; }
}
}
public enum DtrControl : int
{
/// <summary>
/// Disables the DTR line when the device is opened and leaves it disabled.
/// </summary>
Disable = 0,
/// <summary>
/// Enables the DTR line when the device is opened and leaves it on.
/// </summary>
Enable = 1,
/// <summary>
/// Enables DTR handshaking. If handshaking is enabled, it is an error for the application to adjust the line by
/// using the EscapeCommFunction function.
/// </summary>
Handshake = 2
}
public enum RtsControl : int
{
/// <summary>
/// Disables the RTS line when the device is opened and leaves it disabled.
/// </summary>
Disable = 0,
/// <summary>
/// Enables the RTS line when the device is opened and leaves it on.
/// </summary>
Enable = 1,
/// <summary>
/// Enables RTS handshaking. The driver raises the RTS line when the "type-ahead" (input) buffer
/// is less than one-half full and lowers the RTS line when the buffer is more than
/// three-quarters full. If handshaking is enabled, it is an error for the application to
/// adjust the line by using the EscapeCommFunction function.
/// </summary>
Handshake = 2,
/// <summary>
/// Specifies that the RTS line will be high if bytes are available for transmission. After
/// all buffered bytes have been sent, the RTS line will be low.
/// </summary>
Toggle = 3
}
public enum Parity : byte
{
None = 0,
Odd = 1,
Even = 2,
Mark = 3,
Space = 4,
}
public enum StopBits : byte
{
One = 0,
OnePointFive = 1,
Two = 2
}
[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool ReadFile(IntPtr handle,
byte[] buffer, uint toRead, ref uint read, IntPtr lpOverLapped);
[DllImport("msvcrt.dll", EntryPoint = "memset", CallingConvention = CallingConvention.Cdecl, SetLastError = false)]
public static extern IntPtr MemSet(IntPtr dest, int c, int byteCount);
[DllImport("kernel32.dll", SetLastError = true)]
static extern bool SetCommTimeouts(IntPtr hFile, [In] ref COMMTIMEOUTS
lpCommTimeouts);
struct COMMTIMEOUTS
{
public UInt32 ReadIntervalTimeout;
public UInt32 ReadTotalTimeoutMultiplier;
public UInt32 ReadTotalTimeoutConstant;
public UInt32 WriteTotalTimeoutMultiplier;
public UInt32 WriteTotalTimeoutConstant;
}
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern IntPtr CreateFile(
[MarshalAs(UnmanagedType.LPTStr)] string filename,
[MarshalAs(UnmanagedType.U4)] FileAccess access,
[MarshalAs(UnmanagedType.U4)] FileShare share,
IntPtr securityAttributes, // optional SECURITY_ATTRIBUTES struct or IntPtr.Zero
[MarshalAs(UnmanagedType.U4)] FileMode creationDisposition,
[MarshalAs(UnmanagedType.U4)] FileAttributes flagsAndAttributes,
IntPtr templateFile);
struct FILE
{
IntPtr _ptr;
int _cnt;
IntPtr _base;
int _flag;
int _file;
int _charbuf;
int _bufsiz;
IntPtr _tmpfname;
};
[DllImport("kernel32.dll")]
static extern bool WriteFile(IntPtr hFile, byte[] lpBuffer,
uint nNumberOfBytesToWrite, out uint lpNumberOfBytesWritten,
IntPtr lpOverLapped);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool FlushFileBuffers(IntPtr handle);
public bool InitSerialComms()
{
FILE file = new FILE();
COMMTIMEOUTS timeouts;
Dcb dcb = new Dcb();
long len;
char[] name = new char[10];
char[] settings = new char[40];
string str;
// Form the initialization file name
sprintf_s(str, 800, "%s\\SerialComms.ini", path);
// Open the initialization file
fopen_s(&file, str, "r");
// Check for errors
if (file)
{
Console.WriteLine("Error: cannot open file %s\n");
return false;
}
// Scan the serial port name
fgets(name, 10, file);
len = strlen(name);
name[len - 1] = 0;
// Scan the serial port settings
fgets(settings, 40, file);
len = settings.Length;
settings[len - 1] = 0;
// Scan the timeout settings
fgets(str, 40, file); len = strlen(str); string[len - 1] = 0;
sscanf_s(str, "%d,%d,%d,%d,%d",
&timeouts.ReadIntervalTimeout,
&timeouts.ReadTotalTimeoutConstant,
&timeouts.ReadTotalTimeoutMultiplier,
&timeouts.WriteTotalTimeoutConstant,
&timeouts.WriteTotalTimeoutMultiplier);
// Close the initialization file
fclose(file);
// Open the serial port
port = CreateFile(name, GENERIC_READ | GENERIC_WRITE,
0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
// Check for errors
if (port == INVALID_HANDLE_VALUE)
{
// Report the error and return
fprintf(stderr, "Error: cannot open serial port %s\n", name);
fflush(stderr);
return false;
}
// Build the serial port device control block
MemSet(dcb., 0, sizeof(DCB));
dcb.DCBlength = sizeof(DCB);
if (!BuildCommDCB(settings, &dcb))
{
// Report the error and return
fprintf(stderr, "Error: cannot create device control block for %s\n", name);
CloseHandle(port);
fflush(stderr);
return false;
}
// Configure the serial port
if (!SetCommState(port, &dcb))
{
// Report the error and return
fprintf(stderr, "Error: cannot configure serial port %s\n", name);
CloseHandle(port);
fflush(stderr);
return false;
}
// Set the timeouts for the serial port
if (!SetCommTimeouts(port, &timeouts))
{
// Report the error and return
fprintf(stderr, "Error: cannot set timeouts for %s\n", name);
CloseHandle(port);
fflush(stderr);
return false;
}
// Success
return true;
}
bool ReceiveReply(IntPtr port, ref byte[] reply, ref byte num)
{
uint num_read = 0;
uint num_to_read = 255;
ushort crc = 0XFFFF;
byte i, j;
// Clear the reply buffer
//reply = new byte[255];
num = 0;
// Read the data
if (!ReadFile(port, reply, num_to_read, ref num_read, IntPtr.Zero)) return false;
// Check number of bytes that were read
if (num_read < 2) return false;
// Check number of bytes that were read
if (num_read > 255) return false;
// Form the CRC
for (i = 0; i < num_read - 2; i++)
{
crc ^= reply[i];
for (j = 0; j < 8; j++)
{
ushort flag = (ushort) (crc & 0X0001);
crc >>= 1;
//TODO: risky flag check
if (flag == 0) crc ^= 0XA001;
}
}
// Check the CRC
if (reply[i++] != (crc & 0X00FF)) return false;
if (reply[i++] != (crc & 0XFF00) >> 8) return false;
num = (byte)(num_read - 2);
// Success
return true;
}
public static bool SendRequest(IntPtr port, ref byte[] request, ref byte num)
{
ushort crc = 0XFFFF;
byte i, j;
// Check number of bytes
if (num > 253) return false;
// Set number of bytes to write
uint num_to_write = num;
// Form the CRC
for (i = 0; i < num_to_write; i++)
{
crc ^= request[i];
for (j = 0; j < 8; j++)
{
ushort flag = (ushort) (crc & 0X0001);
crc >>= 1; if (flag == 0) crc = (ushort) (crc ^ 0XA001);
}
}
// Set the CRC bytes in the request
request[num_to_write++] = (byte) (crc & 0X00FF);
request[num_to_write++] = (byte) ((crc & 0XFF00) >> 8);
// Send the request
if (!WriteFile(port, request, num_to_write, out uint _, IntPtr.Zero)) return false;
string text = request.ToString().Substring(0, (int) num_to_write).Replace("\r\n", " ");
// Flush the serial line
if (!FlushFileBuffers(port)) return false;
// Success
return true;
}

You don't need sprintf-family functions in higher level languages like C# since they normally allow string concatenation and assignment with the simple = and += operators.
Just write idiomatic C# code for it:
str = path + "\\SerialComms.ini";
Commenter #itsme86 points out that for the task of building a path, you should instead use Path.Combine:
Path.Combine(path, "SerialComms.ini");

How to print PDF to ZPL (Zebra Printers) using c#?

ZEBRA PRINTERS uses the native commands called ZPL programming language, printing PDF to the printers usually do not work, the best solution for printing using C# is?
I created this question and answer as I could not find an effective solution on the Internet, and this one will help a lot of people with this issue

The best solution below:
Requirement: Install the free library Ghostscript 32 bits in the computer
https://www.ghostscript.com/download.html
Main methods: pdfbase64 to ZPL or Stream pdf to ZPL
public static List<string> ZplFromPdf(string pdfBase64, int dpi = 300)
{
return ZplFromPdf(new MemoryStream(Convert.FromBase64String(pdfBase64)), new Size(0,0), dpi);
}
public static List<string> ZplFromPdf(Stream pdf, Size size, int dpi = 300)
{
var zpls = new List<string>();
if (size == new Size(0, 0))
{
size = new Size(812, 1218);
}
using (var rasterizer = new GhostscriptRasterizer())
{
rasterizer.Open(pdf);
var images = new List<Image>();
for (int pageNumber = 1; pageNumber <= rasterizer.PageCount; pageNumber++)
{
var bmp = new Bitmap(rasterizer.GetPage(dpi, dpi, pageNumber), size.Width, size.Height);
var zpl = new StringBuilder();
zpl.Append(ZPLHelper.GetGrfStoreCommand("R:LBLRA2.GRF", bmp));
zpl.Append("^XA^FO0,0^XGR:LBLRA2.GRF,1,1^FS^XZ");
zpl.Append("^XA^IDR:LBLRA2.GRF^FS^XZ");
zpls.Add(zpl.ToString());
}
return zpls;
}
}
Core methods
public class ZPLHelper
{
static Regex regexFilename = new Regex("^[REBA]:[A-Z0-9]{1,8}\\.GRF$");
public static bool PrintLabelBase64Image(string printerName, string base64Image, string jobName = "label")
{
try
{
var bmpLabel = Base64ToBitmap(base64Image);
var baseStream = new MemoryStream();
var tw = new StreamWriter(baseStream, Encoding.UTF8);
tw.WriteLine(GetGrfStoreCommand("R:LBLRA2.GRF", bmpLabel));
tw.WriteLine(GetGrfPrintCommand("R:LBLRA2.GRF"));
tw.WriteLine(GetGrfDeleteCommand("R:LBLRA2.GRF"));
tw.Flush();
baseStream.Position = 0;
var gdipj = new GdiPrintJob(printerName, GdiPrintJobDataType.Raw, jobName, null);
gdipj.WritePage(baseStream);
gdipj.CompleteJob();
return true;
}
catch (Exception)
{
return false;
}
}
public static bool PrintLabelZpl(string printerName, string zplCommand, string jobName = "label")
{
var baseStream = new MemoryStream();
var tw = new StreamWriter(baseStream, Encoding.UTF8);
tw.WriteLine(zplCommand);
tw.Flush();
baseStream.Position = 0;
var gdiJob = new GdiPrintJob(printerName, GdiPrintJobDataType.Raw, jobName, null);
gdiJob.WritePage(baseStream);
gdiJob.CompleteJob();
return true;
}
private static Bitmap Base64ToBitmap(string base64Image)
{
Image image;
using (var ms = new MemoryStream(Convert.FromBase64String(base64Image)))
{
image = Image.FromStream(ms);
}
return new Bitmap(image);
}
public static string GetGrfStoreCommand(string filename, Bitmap bmpSource)
{
if (bmpSource == null)
{
throw new ArgumentNullException("bmpSource");
}
validateFilename(filename);
var dim = new Rectangle(Point.Empty, bmpSource.Size);
var stride = ((dim.Width + 7) / 8);
var bytes = stride * dim.Height;
using (var bmpCompressed = bmpSource.Clone(dim, PixelFormat.Format1bppIndexed))
{
var result = new StringBuilder();
result.AppendFormat("^XA~DG{2},{0},{1},", stride * dim.Height, stride, filename);
byte[][] imageData = GetImageData(dim, stride, bmpCompressed);
byte[] previousRow = null;
foreach (var row in imageData)
{
appendLine(row, previousRow, result);
previousRow = row;
}
result.Append(#"^FS^XZ");
return result.ToString();
}
}
public static string GetGrfDeleteCommand(string filename)
{
validateFilename(filename);
return string.Format("^XA^ID{0}^FS^XZ", filename);
}
public static string GetGrfPrintCommand(string filename)
{
validateFilename(filename);
return string.Format("^XA^FO0,0^XG{0},1,1^FS^XZ", filename);
}
private static void validateFilename(string filename)
{
if (!regexFilename.IsMatch(filename))
{
throw new ArgumentException("Filename must be in the format "
+ "R:XXXXXXXX.GRF. Drives are R, E, B, A. Filename can "
+ "be alphanumeric between 1 and 8 characters.", "filename");
}
}
unsafe private static byte[][] GetImageData(Rectangle dim, int stride, Bitmap bmpCompressed)
{
byte[][] imageData;
var data = bmpCompressed.LockBits(dim, ImageLockMode.ReadOnly, PixelFormat.Format1bppIndexed);
try
{
byte* pixelData = (byte*)data.Scan0.ToPointer();
byte rightMask = (byte)(0xff << (data.Stride * 8 - dim.Width));
imageData = new byte[dim.Height][];
for (int row = 0; row < dim.Height; row++)
{
byte* rowStart = pixelData + row * data.Stride;
imageData[row] = new byte[stride];
for (int col = 0; col < stride; col++)
{
byte f = (byte)(0xff ^ rowStart[col]);
f = (col == stride - 1) ? (byte)(f & rightMask) : f;
imageData[row][col] = f;
}
}
}
finally
{
bmpCompressed.UnlockBits(data);
}
return imageData;
}
private static void appendLine(byte[] row, byte[] previousRow, StringBuilder baseStream)
{
if (row.All(r => r == 0))
{
baseStream.Append(",");
return;
}
if (row.All(r => r == 0xff))
{
baseStream.Append("!");
return;
}
if (previousRow != null && MatchByteArray(row, previousRow))
{
baseStream.Append(":");
return;
}
byte[] nibbles = new byte[row.Length * 2];
for (int i = 0; i < row.Length; i++)
{
nibbles[i * 2] = (byte)(row[i] >> 4);
nibbles[i * 2 + 1] = (byte)(row[i] & 0x0f);
}
for (int i = 0; i < nibbles.Length; i++)
{
byte cPixel = nibbles[i];
int repeatCount = 0;
for (int j = i; j < nibbles.Length && repeatCount <= 400; j++)
{
if (cPixel == nibbles[j])
{
repeatCount++;
}
else
{
break;
}
}
if (repeatCount > 2)
{
if (repeatCount == nibbles.Length - i
&& (cPixel == 0 || cPixel == 0xf))
{
if (cPixel == 0)
{
if (i % 2 == 1)
{
baseStream.Append("0");
}
baseStream.Append(",");
return;
}
else if (cPixel == 0xf)
{
if (i % 2 == 1)
{
baseStream.Append("F");
}
baseStream.Append("!");
return;
}
}
else
{
baseStream.Append(getRepeatCode(repeatCount));
i += repeatCount - 1;
}
}
baseStream.Append(cPixel.ToString("X"));
}
}
private static string getRepeatCode(int repeatCount)
{
if (repeatCount > 419)
throw new ArgumentOutOfRangeException();
int high = repeatCount / 20;
int low = repeatCount % 20;
const string lowString = " GHIJKLMNOPQRSTUVWXY";
const string highString = " ghijklmnopqrstuvwxyz";
string repeatStr = "";
if (high > 0)
{
repeatStr += highString[high];
}
if (low > 0)
{
repeatStr += lowString[low];
}
return repeatStr;
}
private static bool MatchByteArray(byte[] row, byte[] previousRow)
{
for (int i = 0; i < row.Length; i++)
{
if (row[i] != previousRow[i])
{
return false;
}
}
return true;
}
}
internal static class NativeMethods
{
#region winspool.drv
#region P/Invokes
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool OpenPrinter(string szPrinter, out IntPtr hPrinter, IntPtr pd);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool ClosePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern UInt32 StartDocPrinter(IntPtr hPrinter, Int32 level, IntPtr di);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool EndDocPrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool StartPagePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool EndPagePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool WritePrinter(
// 0
IntPtr hPrinter,
[MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2)] byte[] pBytes,
// 2
UInt32 dwCount,
out UInt32 dwWritten);
#endregion
#region Structs
[StructLayout(LayoutKind.Sequential)]
internal struct DOC_INFO_1
{
[MarshalAs(UnmanagedType.LPWStr)]
public string DocName;
[MarshalAs(UnmanagedType.LPWStr)]
public string OutputFile;
[MarshalAs(UnmanagedType.LPWStr)]
public string Datatype;
}
#endregion
#endregion
}
/// <summary>
/// Represents a print job in a spooler queue
/// </summary>
public class GdiPrintJob
{
IntPtr PrinterHandle;
//IntPtr DocHandle;
/// <summary>
/// The ID assigned by the print spooler to identify the job
/// </summary>
public UInt32 PrintJobID { get; private set; }
/// <summary>
/// Create a print job with a enumerated datatype
/// </summary>
/// <param name="PrinterName"></param>
/// <param name="dataType"></param>
/// <param name="jobName"></param>
/// <param name="outputFileName"></param>
public GdiPrintJob(string PrinterName, GdiPrintJobDataType dataType, string jobName, string outputFileName)
: this(PrinterName, translateType(dataType), jobName, outputFileName)
{
}
/// <summary>
/// Create a print job with a string datatype
/// </summary>
/// <param name="PrinterName"></param>
/// <param name="dataType"></param>
/// <param name="jobName"></param>
/// <param name="outputFileName"></param>
public GdiPrintJob(string PrinterName, string dataType, string jobName, string outputFileName)
{
if (string.IsNullOrWhiteSpace(PrinterName))
throw new ArgumentNullException("PrinterName");
if (string.IsNullOrWhiteSpace(dataType))
throw new ArgumentNullException("PrinterName");
IntPtr hPrinter;
if (!NativeMethods.OpenPrinter(PrinterName, out hPrinter, IntPtr.Zero))
throw new Win32Exception();
this.PrinterHandle = hPrinter;
NativeMethods.DOC_INFO_1 docInfo = new NativeMethods.DOC_INFO_1()
{
DocName = jobName,
Datatype = dataType,
OutputFile = outputFileName
};
IntPtr pDocInfo = Marshal.AllocHGlobal(Marshal.SizeOf(docInfo));
RuntimeHelpers.PrepareConstrainedRegions();
try
{
Marshal.StructureToPtr(docInfo, pDocInfo, false);
UInt32 docid = NativeMethods.StartDocPrinter(hPrinter, 1, pDocInfo);
if (docid == 0)
throw new Win32Exception();
this.PrintJobID = docid;
}
finally
{
Marshal.FreeHGlobal(pDocInfo);
}
}
/// <summary>
/// Write the data of a single page or a precomposed PCL document
/// </summary>
/// <param name="data"></param>
public void WritePage(Stream data)
{
if (data == null)
throw new ArgumentNullException("data");
if (!data.CanRead && !data.CanWrite)
throw new ObjectDisposedException("data");
if (!data.CanRead)
throw new NotSupportedException("stream is not readable");
if (!NativeMethods.StartPagePrinter(this.PrinterHandle))
throw new Win32Exception();
byte[] buffer = new byte[0x14000]; /* 80k is Stream.CopyTo default */
uint read = 1;
while ((read = (uint)data.Read(buffer, 0, buffer.Length)) != 0)
{
UInt32 written;
if (!NativeMethods.WritePrinter(this.PrinterHandle, buffer, read, out written))
throw new Win32Exception();
if (written != read)
throw new InvalidOperationException("Error while writing to stream");
}
if (!NativeMethods.EndPagePrinter(this.PrinterHandle))
throw new Win32Exception();
}
/// <summary>
/// Complete the current job
/// </summary>
public void CompleteJob()
{
if (!NativeMethods.EndDocPrinter(this.PrinterHandle))
throw new Win32Exception();
}
#region datatypes
private readonly static string[] dataTypes = new string[]
{
// 0
null,
"RAW",
// 2
"RAW [FF appended]",
"RAW [FF auto]",
// 4
"NT EMF 1.003",
"NT EMF 1.006",
// 6
"NT EMF 1.007",
"NT EMF 1.008",
// 8
"TEXT",
"XPS_PASS",
// 10
"XPS2GDI"
};
private static string translateType(GdiPrintJobDataType type)
{
return dataTypes[(int)type];
}
#endregion
}
public enum GdiPrintJobDataType
{
Unknown = 0,
Raw = 1,
RawAppendFF = 2,
RawAuto = 3,
NtEmf1003 = 4,
NtEmf1006 = 5,
NtEmf1007 = 6,
NtEmf1008 = 7,
Text = 8,
XpsPass = 9,
Xps2Gdi = 10
}

You might be interested in my NuGet package for converting PDF files into ZPL code.
The official Zebra SDK might contain a conversion but I haven't checked (not sure about the licensing here).
Adapting your previous code for the first page would be
public static string ZplFromPdf(string pdfBase64, int dpi = 300)
{
return PDFtoZPL.Conversion.ConvertPdfPage(pdfBase64, dpi: dpi);
}
Disclaimer: I ran into the same problem, stitched together ZPL code found on the internet and bundled it into a tiny .NET API.

C# Easyhook Winsock WS2_32.dll,connect hook Socks5

I'm trying to hook the winsock connect function and route the TCP connection through socks5 proxy /w auth.
This works if the socket is a blocking socket, but while using firefox ( nonblocking sockets ) I get a lot of 10035, 10022 winsock Errors.
How can i determine if it's a nonblocking / blocking socket?
I would really appreciate any hints or ideas to achieve the functionality to hook the wsock connect function and route tcp traffic through a socks5 server.
I can put the demo application on github if anybody wants to test it. ( Works with any version of firefox )
Edit1: https://github.com/duketwo/WinsockConnectHookSocks5/
( You have to edit the proxy information in WSockConnectHook/HookManager.cs and the path of firefox in Injector/MainForm.cs )
Edit2: It's easyhook which is causing the trouble, anything after the original function call doesn't work properly.
Edit3: Seems like i got it working with many flaws, in fact it is required differentiate between nonblocking sockets and blocking sockets. Any ideas how to achieve this?
Edit4: Windows doesn't offer any method to retrieve the blocking-attribute of a socket, so I might have to hook the ioctlsocket function to keep track of the blocking status of the sockets.
Thanks
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using EasyHook;
using System.IO;
using System.Windows.Forms;
namespace WSockConnectHook
{
public class WinSockConnectController : IDisposable, IHook
{
[UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Ansi, SetLastError = true)]
private delegate int WinsockConnectDelegate(IntPtr s, IntPtr addr, int addrsize);
[DllImport("WS2_32.dll", SetLastError = true)]
public static extern int connect(IntPtr s, IntPtr addr, int addrsize);
[StructLayout(LayoutKind.Sequential, Size = 16)]
public struct sockaddr_in
{
public const int Size = 16;
public short sin_family;
public ushort sin_port;
public struct in_addr
{
public uint S_addr;
public struct _S_un_b
{
public byte s_b1, s_b2, s_b3, s_b4;
}
public _S_un_b S_un_b;
public struct _S_un_w
{
public ushort s_w1, s_w2;
}
public _S_un_w S_un_w;
}
public in_addr sin_addr;
}
[DllImport("ws2_32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern int WSAGetLastError();
[DllImport("ws2_32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern void WSASetLastError(int set);
[DllImport("Ws2_32.dll", CharSet = CharSet.Ansi)]
public static extern uint inet_addr(string cp);
[DllImport("Ws2_32.dll")]
public static extern ushort htons(ushort hostshort);
[DllImport("ws2_32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern IntPtr socket(short af, short socket_type, int protocol);
[DllImport("Ws2_32.dll")]
public static extern int send(IntPtr s, IntPtr buf, int len, int flags);
[DllImport("Ws2_32.dll")]
public static extern int recv(IntPtr s, IntPtr buf, int len, int flags);
[DllImport("ws2_32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern int closesocket(IntPtr s);
[DllImport("Ws2_32.dll")]
public static extern ushort ntohs(ushort netshort);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern void SetLastError(int errorCode);
private string _name;
private LocalHook _hook;
public bool Error { get; set; }
public string Name { get; set; }
private string proxyIp, proxyPort, proxyUser, proxyPass;
public WinSockConnectController(IntPtr address, string proxyIp, string proxyPort, string proxyUser, string proxyPass)
{
this.Name = typeof(WinSockConnectController).Name;
this.proxyIp = proxyIp;
this.proxyPort = proxyPort;
this.proxyUser = proxyUser;
this.proxyPass = proxyPass;
try
{
_name = string.Format("WinsockHook_{0:X}", address.ToInt32());
_hook = LocalHook.Create(address, new WinsockConnectDelegate(WinsockConnectDetour), this);
_hook.ThreadACL.SetExclusiveACL(new Int32[] { 1 });
}
catch (Exception)
{
this.Error = true;
}
}
private object wSockLock = new object();
private int WinsockConnectDetour(IntPtr s, IntPtr addr, int addrsize)
{
lock (wSockLock)
{
// retrieve remote ip
sockaddr_in structure = (sockaddr_in)Marshal.PtrToStructure(addr, typeof(sockaddr_in));
string remoteIp = new System.Net.IPAddress(structure.sin_addr.S_addr).ToString();
ushort remotePort = ntohs(structure.sin_port);
HookManager.Log("Ip: " + remoteIp + " Port: " + remotePort.ToString() + " Addrsize: " + addrsize);
if (!proxyIp.Equals(""))
//if (!proxyIp.Equals(""))
{
// connect to socks5 server
SetAddr(s, addr, proxyIp, proxyPort);
var result = Connect(s, addr, addrsize);
if (result == -1)
return -1;
// send socks 5 request
IntPtr socksProtocolRequest = SetUpSocks5Request();
result = send(s, socksProtocolRequest, 4, 0);
if (result == -1)
return -1;
// retrieve server repsonse
var response = Recieve(s, 2);
if (response == IntPtr.Zero)
return -1;
byte[] recvBytes = new byte[2] { Marshal.ReadByte(response), Marshal.ReadByte(response, 1) };
if (recvBytes[1] == 255)
{
HookManager.Log("No authentication method was accepted by the proxy server");
return -1;
}
if (recvBytes[0] != 5)
{
HookManager.Log("No SOCKS5 proxy");
return -1;
}
// if auth request response, send authenicate request
if (recvBytes[1] == 2)
{
int length = 0;
var authenticateRequest = SetUpAuthenticateRequest(proxyUser, proxyPass, out length);
result = Send(s, authenticateRequest, length);
response = Recieve(s, 2);
if (response == IntPtr.Zero)
return -1;
recvBytes = new byte[2] { Marshal.ReadByte(response), Marshal.ReadByte(response, 1) };
if (recvBytes[1] != 0)
{
HookManager.Log("Proxy: incorrect username/password");
return -1;
}
}
// request bind with server
var bindRequest = SetUpBindWithRemoteHost(remoteIp, remotePort);
result = Send(s, bindRequest, 10);
if (result == -1)
return -1;
// response
response = Recieve(s, 10);
if (response == IntPtr.Zero)
return -1;
if (!VerifyBindResponse(response))
return -1;
// success
WSASetLastError(0);
SetLastError(0);
// clean memory
foreach (var ptr in allocatedMemory)
Marshal.FreeHGlobal(ptr);
allocatedMemory.Clear();
return 0;
}
else
{
var result = connect(s, addr, addrsize);
return result;
}
}
}
private int Connect(IntPtr socket, IntPtr addr, int addrsize)
{
var result = connect(socket, addr, addrsize);
while (result == -1)
{
var errorcode = WSAGetLastError();
HookManager.Log("Error: " + errorcode);
if (errorcode == 10056)
break;
if (errorcode == 10037)
break;
if (errorcode != 10035 && errorcode != 10037)
return -1;
//flag = 1;
result = connect(socket, addr, addrsize);
}
return result;
}
private int Send(IntPtr socket, IntPtr buf, int len)
{
var result = send(socket, buf, len, 0);
while (result == -1)
{
var errorcode = WSAGetLastError();
HookManager.Log("Error: " + errorcode);
if (errorcode == 10056)
break;
if (errorcode == 10037)
break;
if (errorcode != 10035 && errorcode != 10037)
return -1;
result = send(socket, buf, 4, 0);
}
return result;
}
private List<IntPtr> allocatedMemory = new List<IntPtr>();
private IntPtr Recieve(IntPtr socket, int len)
{
var buffer = Marshal.AllocHGlobal(len);
allocatedMemory.Add(buffer);
var result = recv(socket, buffer, len, 0);
if (result == -1)
{
HookManager.Log("Error2: " + WSAGetLastError());
return IntPtr.Zero;
}
return buffer;
}
private IntPtr RecieveAuth(IntPtr socket, int len)
{
var buffer = Marshal.AllocHGlobal(len);
allocatedMemory.Add(buffer);
var result = recv(socket, buffer, len, 0);
if (result == -1)
{
HookManager.Log("Error3: " + WSAGetLastError());
return IntPtr.Zero; ;
}
if (result == 0)
return buffer;
if (result != 2)
{
HookManager.Log("Proxy: Bad response from server");
return IntPtr.Zero;
}
return buffer;
}
private IntPtr RecieveBind(IntPtr socket, int len)
{
var buffer = Marshal.AllocHGlobal(len);
allocatedMemory.Add(buffer);
var result = recv(socket, buffer, len, 0);
if (result == -1)
{
HookManager.Log("Error3: " + WSAGetLastError());
return IntPtr.Zero; ;
}
if (result == 0)
return buffer;
if (result != 10)
{
HookManager.Log("Proxy: Bad response from server");
return IntPtr.Zero;
}
return buffer;
}
private void SetAddr(IntPtr socket, IntPtr addr, string ip, string port)
{
sockaddr_in structure = (sockaddr_in)Marshal.PtrToStructure(addr, typeof(sockaddr_in));
string originalip = new System.Net.IPAddress(structure.sin_addr.S_addr).ToString();
ushort originalport = ntohs(structure.sin_port);
structure.sin_addr.S_addr = inet_addr(ip);
structure.sin_port = htons(Convert.ToUInt16(port));
Marshal.StructureToPtr(structure, addr, true);
structure = (sockaddr_in)Marshal.PtrToStructure(addr, typeof(sockaddr_in));
}
private IntPtr SetUpSocks5Request()
{
var initialRequest = Marshal.AllocHGlobal(4);
Marshal.WriteByte(initialRequest, Convert.ToByte(5));
Marshal.WriteByte(initialRequest + 1, Convert.ToByte(2));
Marshal.WriteByte(initialRequest + 2, Convert.ToByte(0));
Marshal.WriteByte(initialRequest + 3, Convert.ToByte(2));
return initialRequest;
}
private IntPtr SetUpAuthenticateRequest(string username, string password, out int index)
{
index = 0;
var size = 3 + Encoding.Default.GetBytes(username).Length + Encoding.Default.GetBytes(password).Length;
var authenticateBuffer = Marshal.AllocHGlobal(size);
Marshal.WriteByte(authenticateBuffer + index++, Convert.ToByte(1));
Marshal.WriteByte(authenticateBuffer + index++, Convert.ToByte(username.Length));
byte[] rawBytes;
if (username.Length > 0)
{
rawBytes = Encoding.Default.GetBytes(username);
for (int i = 0; i < rawBytes.Length; i++)
{
Marshal.WriteByte(authenticateBuffer + index++, rawBytes[i]);
}
}
Marshal.WriteByte(authenticateBuffer + index++, Convert.ToByte(password.Length));
if (password.Length > 0)
{
rawBytes = Encoding.Default.GetBytes(password);
for (int i = 0; i < rawBytes.Length; i++)
{
Marshal.WriteByte(authenticateBuffer + index++, rawBytes[i]);
}
}
return authenticateBuffer;
}
private IntPtr SetUpBindWithRemoteHost(string eveIP, ushort evePort)
{
var bindWithEveBuffer = Marshal.AllocHGlobal(10);
var iplist = eveIP.Split('.').ToList();
byte[] portbyte = BitConverter.GetBytes(evePort).Reverse().ToArray();
byte[] newbyte = new byte[2];
int indexy = 0;
foreach (var byty in portbyte)
{
newbyte[indexy] = byty;
indexy++;
}
// bind with remote server
Marshal.WriteByte(bindWithEveBuffer, Convert.ToByte(5));
Marshal.WriteByte(bindWithEveBuffer + 1, Convert.ToByte(1));
Marshal.WriteByte(bindWithEveBuffer + 2, Convert.ToByte(0));
Marshal.WriteByte(bindWithEveBuffer + 3, Convert.ToByte(1));
Marshal.WriteByte(bindWithEveBuffer + 4, Convert.ToByte(iplist[0]));
Marshal.WriteByte(bindWithEveBuffer + 5, Convert.ToByte(iplist[1]));
Marshal.WriteByte(bindWithEveBuffer + 6, Convert.ToByte(iplist[2]));
Marshal.WriteByte(bindWithEveBuffer + 7, Convert.ToByte(iplist[3]));
Marshal.WriteByte(bindWithEveBuffer + 8, newbyte[0]);
Marshal.WriteByte(bindWithEveBuffer + 9, newbyte[1]);
return bindWithEveBuffer;
}
private bool VerifyBindResponse(IntPtr buffer)
{
var recvBytes = new byte[10] { Marshal.ReadByte(buffer), Marshal.ReadByte(buffer, 1), Marshal.ReadByte(buffer, 2), Marshal.ReadByte(buffer, 3), Marshal.ReadByte(buffer, 4), Marshal.ReadByte(buffer, 5), Marshal.ReadByte(buffer, 6), Marshal.ReadByte(buffer, 7), Marshal.ReadByte(buffer, 8), Marshal.ReadByte(buffer, 9) };
if (recvBytes[1] != 0)
{
if (recvBytes[1] == 1)
HookManager.Log("General failure");
if (recvBytes[1] == 2)
HookManager.Log("connection not allowed by ruleset");
if (recvBytes[1] == 3)
HookManager.Log("network unreachable");
if (recvBytes[1] == 4)
HookManager.Log("host unreachable");
if (recvBytes[1] == 5)
HookManager.Log("connection refused by destination host");
if (recvBytes[1] == 6)
HookManager.Log("TTL expired");
if (recvBytes[1] == 7)
HookManager.Log("command not supported / protocol error");
if (recvBytes[1] == 8)
HookManager.Log("address type not supported");
HookManager.Log("Proxy: Connection error binding eve server");
return false;
}
return true;
}
public void Dispose()
{
if (_hook == null)
return;
_hook.Dispose();
_hook = null;
}
}
}

System.AccessViolationException:Attempted to read or write protected memory

I have a problem about production of a C# wrapper starting from C++ unmanaged library. Everytime I fall into a System.AccessViolationException:Attempted to read or write protected memory. I know probably it depends on the way I translate structures and their elements from C++ to C#, but Idon't know how to solve.
Could someone help me?
C++ code:
typedef struct VBLEnvironmentVariable_t
{
VBLObjectHeader mHeader;
DWORD mNameLength;
DWORD mDataLength;
LPSTR mName;
LPBYTE mData;
} VBLEnvironmentVariable;
typedef struct VBLAppTrigger_t
{
VBLObjectHeader mHeader;
ULONGLONG mPreTriggerTime;
ULONGLONG mPostTriggerTime;
WORD mChannel;
WORD mFlags;
DWORD mAppSecific2;
} VBLAppTrigger;
//signature
BLAPI( BOOL) BLWriteObject( HANDLE hFile, VBLObjectHeaderBase* pBase);
//how function is called
int write_test( LPCTSTR pFileName, LPDWORD pWritten)
{
if ( NULL == pWritten)
{
return -1;
}
*pWritten = 0;
/* open file */
hFile = BLCreateFile( pFileName, GENERIC_WRITE);
if ( INVALID_HANDLE_VALUE == hFile)
{
return -1;
}
/* set applicaton information */
/* bSuccess = BLSetApplication( hFile, BL_APPID_UNKNOWN, 1, 0, 0); */
bSuccess = BLSetApplication( hFile, BL_APPID_CANCASEXLLOG, 1, 0, 1);
GetSystemTime( &systemTime);
bSuccess = bSuccess && BLSetMeasurementStartTime( hFile, &systemTime);
/* set write options */
bSuccess = bSuccess && BLSetWriteOptions( hFile, 6, 0);
if ( bSuccess)
{
// setup object headers
appTrigger.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
appTrigger.mHeader.mBase.mHeaderSize = sizeof( appTrigger.mHeader);
appTrigger.mHeader.mBase.mHeaderVersion = 1;
appTrigger.mHeader.mBase.mObjectSize = sizeof( VBLAppTrigger);
appTrigger.mHeader.mBase.mObjectType = BL_OBJ_TYPE_APP_TRIGGER;
appTrigger.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
message.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
message.mHeader.mBase.mHeaderSize = sizeof( message.mHeader);
message.mHeader.mBase.mHeaderVersion = 1;
message.mHeader.mBase.mObjectSize = sizeof( VBLCANMessage);
message.mHeader.mBase.mObjectType = BL_OBJ_TYPE_CAN_MESSAGE;
message.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
variable_s.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
variable_s.mHeader.mBase.mHeaderSize = sizeof( variable_s.mHeader);
variable_s.mHeader.mBase.mHeaderVersion = 1;
variable_s.mHeader.mBase.mObjectType = BL_OBJ_TYPE_ENV_STRING;
variable_s.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
variable_i.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
variable_i.mHeader.mBase.mHeaderSize = sizeof( variable_i.mHeader);
variable_i.mHeader.mBase.mHeaderVersion = 1;
variable_i.mHeader.mBase.mObjectType = BL_OBJ_TYPE_ENV_INTEGER;
variable_i.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
ethframe.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
ethframe.mHeader.mBase.mHeaderSize = sizeof( ethframe.mHeader);
ethframe.mHeader.mBase.mHeaderVersion = 1;
ethframe.mHeader.mBase.mObjectType = BL_OBJ_TYPE_ETHERNET_FRAME;
ethframe.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
appText.mHeader.mBase.mSignature = BL_OBJ_SIGNATURE;
appText.mHeader.mBase.mHeaderSize = sizeof( appText.mHeader);
appText.mHeader.mBase.mHeaderVersion = 1;
appText.mHeader.mBase.mObjectType = BL_OBJ_TYPE_APP_TEXT;
appText.mHeader.mObjectFlags = BL_OBJ_FLAG_TIME_ONE_NANS;
for ( i = 0; i < 1000; ++i)
{
ethbuffer[i] = ( BYTE)i;
}
for ( i = 0; i < 1000 && bSuccess; ++i)
{
// increment in milliseconds
time = i * 10000000;
// setup app trigger object header
appTrigger.mHeader.mObjectTimeStamp = time;
// write app trigger object
bSuccess = BLWriteObject( hFile, &appTrigger.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
// setup CAN object header
message.mHeader.mObjectTimeStamp = time;
// setup CAN message
message.mChannel = 1;
message.mFlags = CAN_MSG_FLAGS( 0, 0);
message.mDLC = 8;
message.mID = 0x100;
memcpy( message.mData, ( i % 2) ? _T( "01234567") : _T( "76543210"), message.mDLC);
// write CAN message
bSuccess = BLWriteObject( hFile, &message.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
if ( 0 == ( i % 3) && bSuccess)
{
// setup environment variable object headers
variable_s.mHeader.mObjectTimeStamp = time;
variable_i.mHeader.mObjectTimeStamp = time;
// setup environment variables
variable_s.mNameLength = strlen( ENV_NAME1);
variable_s.mDataLength = strlen( ( i % 2) ? ENV_DATA1 : ENV_DATA2);
variable_s.mName = ENV_NAME1;
variable_s.mData = ( i % 2) ? ENV_DATA1 : ENV_DATA2;
variable_s.mHeader.mBase.mObjectSize = sizeof( VBLEnvironmentVariable) + variable_s.mNameLength + variable_s.mDataLength;
variable_i.mNameLength = strlen( ENV_NAME2);
variable_i.mDataLength = sizeof( int);
variable_i.mName = ENV_NAME2;
variable_i.mData = ( LPBYTE)&i;
variable_i.mHeader.mBase.mObjectSize = sizeof( VBLEnvironmentVariable) + variable_i.mNameLength + variable_i.mDataLength;
// write environment variables
bSuccess = BLWriteObject( hFile, &variable_s.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
bSuccess = bSuccess && BLWriteObject( hFile, &variable_i.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
// write ethernet frame
memcpy( ethframe.mSourceAddress, src, sizeof( ethframe.mSourceAddress));
ethframe.mReserved1 = 0;
memcpy( ethframe.mDestinationAddress, dst, sizeof( ethframe.mDestinationAddress));
ethframe.mReserved2 = 0;
ethframe.mType = 0x0800;
ethframe.mTPID = 0;
ethframe.mTCI = 0;
ethframe.mPayLoadLength = ( WORD)i;
ethframe.mPayLoad = ethbuffer;
ethframe.mHeader.mBase.mObjectSize = sizeof( VBLEthernetFrame) + ethframe.mPayLoadLength;
bSuccess = bSuccess && BLWriteObject( hFile, &ethframe.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
// write text
if ( ( i % 100) == 0)
{
char text[128];
sprintf( text, "%d objects written...", *pWritten);
appText.mText = text;
appText.mTextLength = strlen( appText.mText);
appText.mHeader.mBase.mObjectSize = sizeof( VBLAppText) + appText.mTextLength;
bSuccess = bSuccess && BLWriteObject( hFile, &appText.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
}
}
}
appText.mText = "All objects written...";
appText.mTextLength = strlen( appText.mText);
appText.mHeader.mBase.mObjectSize = sizeof( VBLAppText) + appText.mTextLength;
bSuccess = bSuccess && BLWriteObject( hFile, &appText.mHeader.mBase);
*pWritten += bSuccess ? 1 : 0;
}
/* close file */
if ( !BLCloseHandle( hFile))
{
return -1;
}
return bSuccess ? 0 : -1;
}`
C# code:
//translation of C++ struct into C# class
public class VBLEnvVar
{
public VBLEnvVarStruct variable_s;
public VBLEnvVar()
{
variable_s = new BLF_Function.VBLEnvVar.VBLEnvVarStruct();
}
public struct VBLEnvVarStruct
{
public VBLObjectHeader.VBLObjectHeaderStruct mHeader;
public uint NameLength;
public uint DataLength;
public string Name;
[MarshalAsAttribute(UnmanagedType.LPArray)]
public byte[] Data;
}
}
public class VBLAppTrigger
{
public VBLAppTriggerStruct apptrigger;
public VBLAppTrigger()
{
apptrigger = new BLF_Function.VBLAppTrigger.VBLAppTriggerStruct(null);
}
public struct VBLAppTriggerStruct
{
public VBLObjectHeader.VBLObjectHeaderStruct mHeader;
public UInt64 mPreTriggerTime;
public UInt64 mPostTriggerTime;
public ushort mFlags;
public ushort mChannel;
public uint mAppSpecific2;
}
}
[DllImport("binlog.dll")]
public static extern bool BLWriteObject( int Handle,ref BLF_Function.ObjectHeader.ObjHeader pBase);
//how function is called into C# code
public static void Main(string[] args)
{
int written=0;
BLF_Function b = new BLF_Function();
UInt64 time=0;
byte[] ethbuffer = new byte[1500];
bool success=false;
string filename = "provamia.blf";
int Handle = MyBLF.BLCreateFile(filename,b.GENERIC_WRITE);
if (Handle != -1)
{
success = MyBLF.BLSetApplication( Handle, (byte)BLF_Function.FileStatistics.APPID.BL_APPID_UNKNOWN, 1, 0, 1);
//***********
MyBLF.SYSTEMTIME d = new MyBLF.SYSTEMTIME();
MyBLF.GetLocalTime(out d);
MyBLF.SYSTEMTIME* s = &d;
success = MyBLF.BLSetMeasurementStartTime( Handle,ref s);
//*************
if (success)
{
success = MyBLF.BLSetWriteOptions( Handle, 6,0);
if (success)
{
BLF_Function.VBLObjectHeader vblobjectheaderclass = new BLF_Function.VBLObjectHeader();
BLF_Function.ObjectHeader objectheaderclass = new BLF_Function.ObjectHeader();
vblobjectheaderclass.mHeader.baseheader=objectheaderclass.baseheader;
BLF_Function.VBLAppTrigger apptriggerclass = new BLF_Function.VBLAppTrigger();
apptriggerclass.apptrigger.mFlags=(ushort)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
apptriggerclass.apptrigger.mHeader=vblobjectheaderclass.mHeader;
apptriggerclass.apptrigger.mHeader.baseheader.HeaderSize = apptriggerclass.apptrigger.mHeader.GetSize();
apptriggerclass.apptrigger.mHeader.baseheader.HeaderVersion = 1;
apptriggerclass.apptrigger.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
apptriggerclass.apptrigger.mHeader.baseheader.ObjectSize = (ushort)apptriggerclass.GetSize();
apptriggerclass.apptrigger.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_APP_TRIGGER;
apptriggerclass.apptrigger.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
BLF_Function.VBLCANMessage messageclass = new BLF_Function.VBLCANMessage();
messageclass.message.mHeader=vblobjectheaderclass.mHeader;
messageclass.message.mHeader.baseheader.HeaderSize = messageclass.message.mHeader.GetSize();
messageclass.message.mHeader.baseheader.HeaderVersion = 1;
messageclass.message.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
messageclass.message.mHeader.baseheader.ObjectSize = (ushort)messageclass.GetSize();
messageclass.message.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_CAN_MESSAGE;
messageclass.message.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
BLF_Function.VBLEnvVar variable_sclass = new BLF_Function.VBLEnvVar();
variable_sclass.variable_s.mHeader=vblobjectheaderclass.mHeader;
variable_sclass.variable_s.mHeader.baseheader.HeaderSize = variable_sclass.variable_s.mHeader.GetSize();
variable_sclass.variable_s.mHeader.baseheader.HeaderVersion = 1;
variable_sclass.variable_s.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
variable_sclass.variable_s.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_ENV_STRING;
variable_sclass.variable_s.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
BLF_Function.VBLEnvVar variable_iclass = new BLF_Function.VBLEnvVar();
variable_iclass.variable_s.mHeader=vblobjectheaderclass.mHeader;
variable_iclass.variable_s.mHeader.baseheader.HeaderSize = variable_iclass.variable_s.mHeader.GetSize();
variable_iclass.variable_s.mHeader.baseheader.HeaderVersion = 1;
variable_iclass.variable_s.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
variable_iclass.variable_s.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_ENV_INTEGER;
variable_iclass.variable_s.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
BLF_Function.VBLEthernetFrame ethframeclass = new BLF_Function.VBLEthernetFrame();
ethframeclass.ethframe.mHeader=vblobjectheaderclass.mHeader;
ethframeclass.ethframe.mHeader.baseheader.HeaderSize = ethframeclass.ethframe.mHeader.GetSize();
ethframeclass.ethframe.mHeader.baseheader.HeaderVersion = 1;
ethframeclass.ethframe.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
ethframeclass.ethframe.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_ETHERNET_FRAME;
ethframeclass.ethframe.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
BLF_Function.VBLAppText appTextclass = new BLF_Function.VBLAppText();
appTextclass.appText.mHeader=vblobjectheaderclass.mHeader;
appTextclass.appText.mHeader.baseheader.HeaderSize = appTextclass.appText.mHeader.GetSize();
appTextclass.appText.mHeader.baseheader.HeaderVersion = 1;
appTextclass.appText.mHeader.baseheader.signature = objectheaderclass.BL_OBJ_SIGNATURE;
appTextclass.appText.mHeader.baseheader.ObjectSize = (ushort)appTextclass.GetSize();
appTextclass.appText.mHeader.baseheader.ObjectType = (ushort)BLF_Function.ObjectHeader.OBJ_TYPR.BL_OBJ_TYPE_APP_TEXT;
appTextclass.appText.mHeader.mObjectFlags = (uint)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
for (int h=0;h<ethbuffer.Length;h++)
ethbuffer[h]=Convert.ToByte(h & 0xFF);
for (int i = 0; i < 1000 ; ++i)
{
/* increment in milliseconds */
time = (uint)(i * 100000);
/* setup app trigger object header */
apptriggerclass.apptrigger.mHeader.mObjectTimestamp = time;
/* write app trigger object */
success = Scrivi(Handle, apptriggerclass.apptrigger.mHeader.baseheader);////NO ERROR
written += success ? 1 : 0;
if (success)
{
string envdata1="01234567";
string envdata2="76543210";
/* setup CAN object header */
messageclass.message.mHeader.mObjectTimestamp = time;
/* setup CAN message */
messageclass.message.mChannel=1;
messageclass.message.mFlags=(byte)vblobjectheaderclass.BL_OBJ_FLAG_TIME_ONE_NANS;
messageclass.message.mDLC = 8;
messageclass.message.mID = 0x100;
char[] supp = envdata1.ToCharArray();
char[] supp2 = envdata2.ToCharArray();
messageclass.message.Data = new byte[messageclass.message.mDLC];
if ((i%2)==0)
{
for (int g=0;g<supp.Length;g++)
messageclass.message.Data[g] = (byte)supp[g];
}
else
{
for (int g=0;g<supp2.Length;g++)
messageclass.message.Data[g] = (byte)supp2[g];
}
/* write CAN message */
success = Scrivi(Handle, messageclass.message.mHeader.baseheader);////NO ERROR
written += success ? 1 : 0;
if (success)
{
if ((i%3)==0)
{
/* setup environment variable object headers */
variable_sclass.variable_s.mHeader.mObjectTimestamp= time;
/* setup environment variables */
string envname1="EnvString";
string envname2="EnvInt";
char[] suppstring1 = envname1.ToCharArray();
char[] suppstring2 = envname2.ToCharArray();
variable_sclass.variable_s.NameLength = (uint)envname1.Length;
variable_sclass.variable_s.DataLength = (uint)(((i%2)==0)?envdata1.Length:envdata2.Length);
variable_sclass.variable_s.Name = envname1;
variable_sclass.variable_s.Data = new byte[variable_sclass.variable_s.DataLength];
if ((i%2)==0)
{
for (int g=0;g<supp.Length;g++)
variable_sclass.variable_s.Data[g] = Convert.ToByte(supp[g]);
}
else
{
for (int g=0;g<supp2.Length;g++)
variable_sclass.variable_s.Data[g] = Convert.ToByte(supp2[g]);
}
variable_sclass.variable_s.mHeader.baseheader.ObjectSize = 65;
success = Scrivi(Handle, variable_sclass.variable_s.mHeader.baseheader);////ERROR
...........
}
public static bool Scrivi(int a, BLF_Function.ObjectHeader.ObjHeader b)
{
return MyBLF.BLWriteObject( a, ref b);
}
CB

Firstly, the type HANDLE should translate to IntPtr, not int.
Also the sizes of the structs may differ to the original due to structure padding. Use the [Structlayout()]-Attribute in your C#-code to control this.

Change "ref" to "out" everywhere in C# and see that there is no memory allocation issues in c++ code.

Marshalling array of strings to char ** in C#

I'm calling a C DLL function and need to supply the following C struct:
typedef struct
{
char *mTableId;
char **mFieldNames;
int mNumFields;
char *mFilter;
char *mSort;
int mOffset;
int mMaxRecords;
char *mTargetRecordFilter;
int mSurroundingRecordsCount;
int *mOwnerIds;
int mNumOwnerIds;
gsi_bool mCacheFlag;
} SAKESearchForRecordsInput;
The problem is with char **mFieldNames; I've tried marshalling automatically like this:
[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.LPTStr, SizeConst = 9)]
public String[] mFieldNames;
This way I get an error in Marshal.SizeOf() - can't compute the correct size. Then I decided to deal with pointers manually. It's in fact just a pointer to the array of C strings. Here's my code which is leading to
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
So I've screwed up pointers somewhere. The code seems OK to me, where is the bug?
C#:
[StructLayout(LayoutKind.Sequential)]
unsafe public class SAKESearchForRecordsInput {
[MarshalAs(UnmanagedType.LPTStr)]
public String mTableId;
//[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.LPTStr, SizeConst = 9)] // HARDCODED!?!
//public String[] mFieldNames; // char **mFieldNames;
public IntPtr mFieldNames;
public int mNumFields;
[MarshalAs(UnmanagedType.LPTStr)]
public String mFilter;
[MarshalAs(UnmanagedType.LPTStr)]
public String mSort;
public int mOffset;
public int mMaxRecords;
//[MarshalAs(UnmanagedType.LPTStr)]
public IntPtr mTargetRecordFilter;
public int mSurroundingRecordsCount;
public IntPtr mOwnerIds;
public int mNumOwnerIds;
public gsi_bool mCacheFlag;
}
[DllImport("saketestd.dll")]
unsafe static extern void* sakeSearchForRecords(
IntPtr sake,
IntPtr input, //SAKESearchForRecordsInput *
SAKERequestCallback callback, //SAKERequestCallback
IntPtr userData);
unsafe public bool sakeSearchForRecordsE() {
bool ret = false;
try {
searchInput.mTableId = "bbdx_score";
//searchInput.mFieldNames = mFieldNames.to;
searchInput.mFilter = "num_ratings = 0 AND filestore > 0";
searchInput.mSort = "";
searchInput.mOffset = 0;
searchInput.mMaxRecords = 1;
//searchInput.mTargetRecordFilter = "";
searchInput.mSurroundingRecordsCount = 0;
searchInput.mOwnerIds = IntPtr.Zero;
searchInput.mNumOwnerIds = 0;
searchInput.mCacheFlag = true;
int sakeSize = Marshal.SizeOf(sake);
debug.AddLine(this.getMethodName() + ": sizeof(sake): " + sakeSize);
IntPtr pSake = Marshal.AllocHGlobal(sakeSize);
Marshal.StructureToPtr(sake, pSake, true);
int inputSize = Marshal.SizeOf(searchInput);
debug.AddLine(this.getMethodName() + ": sizeof(input): " + inputSize);
IntPtr pInput = Marshal.AllocHGlobal(inputSize);
Marshal.StructureToPtr(searchInput, pInput, true);
IntPtr[] mFieldNamesPtr;
int i;
if (true) { // IntPtr[]
mFieldNamesPtr = new IntPtr[mFieldNames.Length];
i = 0;
foreach (string str in mFieldNames) {
mFieldNamesPtr[i++] = Marshal.StringToHGlobalAnsi(str);
}
//searchInput.mFieldNames = mFieldNamesPtr;
} else {
//searchInput.mFieldNames = mFieldNames;
}
searchInput.mNumFields = mFieldNames.Length;
void* pRequestInternal = null;
void* p = mFieldNamesPtr[0].ToPointer();
searchInput.mFieldNames = (IntPtr)p;
pRequestInternal = sakeSearchForRecords(
pSake,
pInput,
new SAKERequestCallback(this.sakeSearchForRecordsCB),
IntPtr.Zero
);
sake = (SAKEInternal)Marshal.PtrToStructure(pSake, typeof(SAKEInternal));
if (searchRequest == null) {
debug.AddLine(this.getMethodName() + ": mStartRequestResult: " + sake.mStartRequestResult);
} else {
ret = true;
this.searchRequest = (SAKERequestInternal)Marshal.PtrToStructure(
new IntPtr(pRequestInternal),
typeof(SAKERequestInternal)
);
searchInput = (SAKESearchForRecordsInput)Marshal.PtrToStructure(
pInput,
typeof(SAKESearchForRecordsInput)
);
if (true) {
i = 0;
foreach (string str in mFieldNames) {
Marshal.FreeHGlobal(mFieldNamesPtr[i++]);
}
}
PrintStruct ps = new PrintStruct(sake);
debug.AddLine(this.getMethodName() + ": sake: " + ps);
ps = new PrintStruct(searchRequest);
debug.AddLine(this.getMethodName() + ": searchRequest: " + ps.print_r());
ps = new PrintStruct(searchInput);
debug.AddLine(this.getMethodName() + ": searchInput: " + ps.print_r());
}
Marshal.FreeHGlobal(pSake);
Marshal.FreeHGlobal(pInput);
} catch (Exception ex) {
debug.Text += ex.ToString();
}
return ret;
}

The best way to Marshal nasty string pointers, especially double pointers within a struct is to simply use an IntPtr.
public IntPtr mFieldNames;
This will Marshal correctly albeit with a not so useful type. However if you understand the structure of the IntPtr it's very easy to get the resulting strings out.
public static List<string> GetAllStrings(IntPtr ptr, int size) {
var list = new List<string>();
for ( int i = 0; i < size; i++ ) {
var strPtr = (IntPtr)Marshal.PtrToStructure(ptr, typeof(IntPtr));
list.Add(Marshal.PtrToStringUni(strPtr));
ptr = new IntPtr(ptr.ToInt64()+IntPtr.Size);
}
return list;
}
The only real downside is that you will have to manually free the memory

A better way is simply to use unsafe code with sbyte which is the same as c-char (-128 to 127) 1 byte.
You can write yourself some extern functions like alloc_txt, free_txt,etc.. for allocating and freeing from the heap. Mostly when I write with interop I do use unsafe code because IntPtr gets you the address but you still have to use extern functions to get members in the structure it points to or if a primitive have to Marshal methods to extract what the value is.
The only time you have to declare a c# structure as unsafe is if you are using actual pointers which you are not but using MarshalAs instead. I still would prefer you use unsafe pointers via MarshalAs(UnmanagedType.?) which allows you do deal with the members directly.
[Struct(Layout.Sequential)]
public unsafe struct SAKESearchForRecordsInput
{
sbyte*mTableId;
sbyte**mFieldNames;
int mNumFields;
sbyte*mFilter;
sbyte*mSort;
int mOffset;
int mMaxRecords;
char*mTargetRecordFilter;
int mSurroundingRecordsCount;
int*mOwnerIds;
int mNumOwnerIds;
bool mCacheFlag;//?don't know what the typedef for the bytes
};