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MVC WebAPI return multiple images

I have 3 images in a directory but my code always returns one of them. I'd like to return 3 images image1.jpg, image2.jpg, image3.jpg and get them in my Xamarin app.
I think returning the result like an array might solve the problem but I don't understand what I need.
var result = new HttpResponseMessage(HttpStatusCode.OK);
MemoryStream ms = new MemoryStream();
for (int i = 0; i < 3; i++)
{
String filePath = HostingEnvironment.MapPath("~/Fotos/Empresas/Comer/" + id + (i + 1) + ".jpg");
FileStream fileStream = new FileStream(filePath, FileMode.OpenOrCreate);
Image image = Image.FromStream(fileStream);
image.Save(ms, ImageFormat.Jpeg);
fileStream.Close();
byte[] bytes = File.ReadAllBytes(filePath);
byte[] length = BitConverter.GetBytes(bytes.Length);
// Write length followed by file bytes to stream
ms.Write(length, 0, 3);
ms.Write(bytes, 0, bytes.Length);
}
result.Content = new StreamContent(ms);
return result;
Now i getting bytes, i edit a little bit the code now
byte[] imageAsBytes = client.GetByteArrayAsync(url).Result;
MemoryStream stream1 = new MemoryStream(imageAsBytes);
img.Source = ImageSource.FromStream(() => { return stream1; });
this is my xamarin code to get images, but i still getting nothing =/

If you just return a memorystream is not easy to differentiate one image from the other in the stream, instead of this, you can return a List of byte arrays, then you can access each position in the array and convert from byte array to image...
Here is a fully functional dotnet core webapi controller :
public class GetImagesController : Controller
{
private readonly IWebHostEnvironment _host;
public GetImagesController(IWebHostEnvironment host)
{
_host = host;
}
[HttpGet("{images}")]
public async Task<List<byte[]>> Get([FromQuery]string images)
{
List<byte[]> imageBytes = new List<byte[]>();
String[] strArray = images.Split(',');
for (int i = 0; i < strArray.Length; i++)
{
String filePath = Path.Combine(_host.ContentRootPath, "images", strArray[i]+".jpg");
byte[] bytes = System.IO.File.ReadAllBytes(filePath);
imageBytes.Add(bytes);
}
return imageBytes;
}
}
This controller can be called like this :
https://localhost:44386/getImages?images=P1,P2,P3
Given that you have a folder called images with files P1.jpg, P2.jpg and P3.jpg under your ContentRooPath.
https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/web-host?view=aspnetcore-3.0

You'll need something in the response to delimit where each image starts and finishes. As a basic solution, you could write the image length as an Int32 and follow it with the image data. On the other end, you'll need to read the 4-byte length followed by that x number of bytes:
[HttpGet]
public HttpResponseMessage Get(string id)
{
var result = new HttpResponseMessage(HttpStatusCode.OK);
String[] strArray = id.Split(',');
var ms = new MemoryStream();
for (int i = 0; i < strArray.Length; i++)
{
String filePath = HostingEnvironment.MapPath("~/Fotos/Empresas/Comer/" + strArray[i] + (i + 1) + ".jpg");
byte[] bytes = File.ReadAllBytes(filePath);
byte[] length = BitConverter.GetBytes(bytes.Length);
// Write length followed by file bytes to stream
ms.Write(length, 0, 4);
ms.Write(bytes, 0, bytes.Length);
}
result.Content = new StreamContent(ms);
return result;
}

FileStream is not working with relative path

I'm trying to use a FileStream with a relative path but it is not working.
var pic = ReadFile("~/Images/money.png");
It is working when I use something like:
var p = GetFilePath();
var pic = ReadFile(p);
the rest of the code(from SO):
public static byte[] ReadFile(string filePath)
{
byte[] buffer;
FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
try
{
int length = (int)fileStream.Length; // get file length
buffer = new byte[length]; // create buffer
int count; // actual number of bytes read
int sum = 0; // total number of bytes read
// read until Read method returns 0 (end of the stream has been reached)
while ((count = fileStream.Read(buffer, sum, length - sum)) > 0)
sum += count; // sum is a buffer offset for next reading
}
finally
{
fileStream.Close();
}
return buffer;
}
public string GetFilePath()
{
return HttpContext.Current.Server.MapPath("~/Images/money.png");
}
I don't get why it is not working because the FileStream constructor allow using relative path.

I'm assuming the folder in your program has the subfolder images, which contains your image file.
\folder\program.exe
\folder\Images\money.jpg
Try without the "~".

I also had the same issue but I solved it by using this code,
Try one of this code, hope it will solve your issue too.
#region GetImageStream
public static Stream GetImageStream(string Image64string)
{
Stream imageStream = new MemoryStream();
if (!string.IsNullOrEmpty(Image64string))
{
byte[] imageBytes = Convert.FromBase64String(Image64string.Substring(Image64string.IndexOf(',') + 1));
using (Image targetimage = BWS.AWS.S3.ResizeImage(System.Drawing.Image.FromStream(new MemoryStream(imageBytes, false)), new Size(1600, 1600), true))
{
targetimage.Save(imageStream, ImageFormat.Jpeg);
}
}
return imageStream;
}
#endregion
2nd one
#region GetImageStream
public static Stream GetImageStream(Stream stream)
{
Stream imageStream = new MemoryStream();
if (stream != null)
{
using (Image targetimage = BWS.AWS.S3.ResizeImage(System.Drawing.Image.FromStream(stream), new Size(1600, 1600), true))
{
targetimage.Save(imageStream, ImageFormat.Jpeg);
}
}
return imageStream;
}
#endregion

File got corrupted when I Read the file's all bytes on list type of object then write a file again Using c#

I've lot of tried to write file from collection of bytes. but file always get corrupted. not sure why its happening. If somebody knows about it would be helpful me more.
Note: Its always working good when I uncomment under while loop this line //AppendAllBytes(pathSource, bytes);
but I need bytes from object. later on I will use this concept on p2p.
namespace Sender
{
static class Program
{
static void Main(string[] args)
{
string pathSource = "../../Ok&SkipButtonForWelcomeToJakayaWindow.jpg";
using (FileStream fsSource = new FileStream(pathSource,
FileMode.Open, FileAccess.Read))
{
// Read the source file into a byte array.
const int numBytesToRead = 100000; // Your amount to read at a time
byte[] bytes = new byte[numBytesToRead];
int numBytesRead = 0;
if (File.Exists(pathSource))
{
Console.WriteLine("File of this name already exist, you want to continue?");
System.IO.FileInfo obj = new System.IO.FileInfo(pathSource);
pathSource = "../../Files/" + Guid.NewGuid() + obj.Extension;
}
int i = 0;
byte[] objBytes = new byte[numBytesRead];
List<FileInfo> objFileInfo = new List<FileInfo>();
Guid fileID = Guid.NewGuid();
FileInfo fileInfo = null;
while (numBytesToRead > 0)
{
// Read may return anything from 0 to numBytesToRead.
int n = fsSource.Read(bytes, numBytesRead, numBytesToRead);
i++;
//AppendAllBytes(pathSource, bytes);
fileInfo = new FileInfo { FileID = fileID, FileBytes = bytes, FileByteID = i };
objFileInfo.Add(fileInfo);
// Break when the end of the file is reached.
if (n == 0)
{
break;
}
// Do here what you want to do with the bytes read (convert to string using Encoding.YourEncoding.GetString())
}
//foreach (var b in objFileInfo.OrderBy(m => m.FileByteID))
//{
// AppendAllBytes(pathSource, b.FileBytes);
//}
foreach (var item in objFileInfo)
{
AppendAllBytes(pathSource, item.FileBytes);
}
fileInfo = null;
}
}
static void AppendAllBytes(string path, byte[] bytes)
{
using (var stream = new FileStream(path, FileMode.Append))
{
stream.Write(bytes, 0, bytes.Length);
}
}
}
class FileInfo
{
public Guid FileID { get; set; }
public int FileByteID { get; set; }
public byte[] FileBytes { get; set; }
}
}

You don't increase numBytesRead and don't decrease numBytesToRead.

objFileInfo contains a List of FileInfo which contains a reference type byte[].
You copy the reference to the bytes when you create a new FileInfo and then repeatedly overwrite those bytes until you reach the end of the file.
byte[] bytes = new byte[numBytesToRead];
//...
List<FileInfo> objFileInfo = new List<FileInfo>();
//...
//...
while (numBytesToRead > 0)
{
int n = fsSource.Read(bytes, numBytesRead, numBytesToRead);
//First time here bytes[0] == the first byte of the file
//Second time here bytes[0] == 10000th byte of file
//...
//The following line should copy the bytes into file info instead of the reference to the existing byte array
fileInfo = new FileInfo { ..., FileBytes = bytes, ... };
objFileInfo.Add(fileInfo);
//First time here objFileInfo[0].FileBytes[0] == first byte of file
//Second time here objFileInfo[0].FileBytes[0] == 10000th byte of file because objFileInfo[All].FileBytes == bytes
//...
}
You can test this by looking in the FileBytes variable for multiple FileInfo. I'd bet the contents look similar

There is two problem in your code :
The block of data is all of size 100000, which cannot work most of time unless the file size is exactly a multiple of it. So, the last block of data will contains 0s.
FileInfo.FileBytes will change, if you change the buffer to something new causing the every single block of data being the identical to the last block read.
using System;
using System.Collections.Generic;
using System.IO;
static class Program
{
static void Main(string[] args)
{
string pathSource = "test.jpg";
using (FileStream fsSource = new FileStream(pathSource, FileMode.Open, FileAccess.Read))
{
// Read the source file into a byte array.
const int BufferSize = 100000; // Your amount to read at a time
byte[] buffer = new byte[BufferSize];
if (File.Exists(pathSource))
{
Console.WriteLine("File of this name already exist, you want to continue?");
System.IO.FileInfo obj = new System.IO.FileInfo(pathSource);
pathSource = "Files/" + Guid.NewGuid() + obj.Extension;
}
int i = 0, offset = 0, bytesRead;
List<FileInfo> objFileInfo = new List<FileInfo>();
Guid fileID = Guid.NewGuid();
while (0 != (bytesRead = fsSource.Read(buffer, offset, BufferSize)))
{
var data = new byte[bytesRead];
Array.Copy(buffer, data, bytesRead);
objFileInfo.Add(new FileInfo { FileID = fileID, FileBytes = data, FileByteID = ++i });
}
foreach (var item in objFileInfo)
{
AppendAllBytes(pathSource, item.FileBytes);
}
}
}
static void AppendAllBytes(string path, byte[] bytes)
{
using (var stream = new FileStream(path, FileMode.Append))
{
stream.Write(bytes, 0, bytes.Length);
}
}
}
class FileInfo
{
public Guid FileID { get; set; }
public int FileByteID { get; set; }
public byte[] FileBytes { get; set; }
}

How to add multiple fpages to fixed document in xps?

My requirement is to create xps document which has 10 pages (say). I am using the following code to create a xps document. Please take a look.
// Create the new document
XpsDocument xd = new XpsDocument("D:\\9780545325653.xps", FileAccess.ReadWrite);
IXpsFixedDocumentSequenceWriter xdSW = xd.AddFixedDocumentSequence();
IXpsFixedDocumentWriter xdW = xdSW.AddFixedDocument();
IXpsFixedPageWriter xpW = xdW.AddFixedPage();
fontURI = AddFontResourceToFixedPage(xpW, #"D:\arial.ttf");
image = AddJpegImageResourceToFixedPage(xpW, #"D:\Single content\20_1.jpg");
StringBuilder pageContents = new StringBuilder();
pageContents.Append(ReadFile(#"D:\Single content\20.fpage\20.fpage", i));
xmlWriter = xpW.XmlWriter;
xmlWriter.WriteRaw(pageContents.ToString());
}
xmlWriter.Close();
xpW.Commit();
// Commit the fixed document
xdW.Commit();
// Commite the fixed document sequence writer
xdSW.Commit();
// Commit the XPS document itself
xd.Close();
}
private static string AddFontResourceToFixedPage(IXpsFixedPageWriter pageWriter, String fontFileName)
{
string fontUri = "";
using (XpsFont font = pageWriter.AddFont(false))
{
using (Stream dstFontStream = font.GetStream())
using (Stream srcFontStream = File.OpenRead(fontFileName))
{
CopyStream(srcFontStream, dstFontStream);
// commit font resource to the package file
font.Commit();
}
fontUri = font.Uri.ToString();
}
return fontUri;
}
private static Int32 CopyStream(Stream srcStream, Stream dstStream)
{
const int size = 64 * 1024; // copy using 64K buffers
byte[] localBuffer = new byte[size];
int bytesRead;
Int32 bytesMoved = 0;
// reset stream pointers
srcStream.Seek(0, SeekOrigin.Begin);
dstStream.Seek(0, SeekOrigin.Begin);
// stream position is advanced automatically by stream object
while ((bytesRead = srcStream.Read(localBuffer, 0, size)) > 0)
{
dstStream.Write(localBuffer, 0, bytesRead);
bytesMoved += bytesRead;
}
return bytesMoved;
}
private static string ReadFile(string filePath,int i)
{
FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite);
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(fs))
{
String line;
// Read and display lines from the file until the end of
// the file is reached.
while ((line = sr.ReadLine()) != null)
{
sb.AppendLine(line);
}
}
string allines = sb.ToString();
//allines = allines.Replace("FontUri=\"/Resources/f7728e4c-2606-4fcb-b963-d2d3f52b013b.odttf\"", "FontUri=\"" + fontURI + "\" ");
//XmlReader xmlReader = XmlReader.Create(fs, new XmlReaderSettings() { IgnoreComments = true });
XMLSerializer serializer = new XMLSerializer();
FixedPage fp = (FixedPage)serializer.DeSerialize(allines, typeof(FixedPage));
foreach (Glyphs glyph in fp.lstGlyphs)
{
glyph.FontUri = fontURI;
}
fp.Path.PathFill.ImageBrush.ImageSource = image;
fs.Close();
string fpageString = serializer.Serialize(fp);
return fpageString;
}
private static string AddJpegImageResourceToFixedPage(IXpsFixedPageWriter pageWriter, String imgFileName)
{
XpsImage image = pageWriter.AddImage("image/jpeg");
using (Stream dstImageStream = image.GetStream())
using (Stream srcImageStream = File.OpenRead(imgFileName))
{
CopyStream(srcImageStream, dstImageStream); // commit image resource to the package file
//image.Commit();
}
return image.Uri.ToString();
}
If you see it, i would have passed single image and single fpage to create a xps document. I want to pass multiple fpages list and image list to create a xps document which has multiple pages..?

You are doing this in the most excruciatingly difficult manner possible. I'd suggest taking the lazy man's route.
Realize that an XpsDocument is just a wrapper on a FixedDocumentSequence, which contains zero or more FixedDocuments, which contains zero or more FixedPages. All these types can be created, manipulated and combined without writing XML.
All you really need to do is create a FixedPage with whatever content on it you need. Here's an example:
static FixedPage CreateFixedPage(Uri imageSource)
{
FixedPage fp = new FixedPage();
fp.Width = 320;
fp.Height = 240;
Grid g = new Grid();
g.HorizontalAlignment = System.Windows.HorizontalAlignment.Center;
g.VerticalAlignment = System.Windows.VerticalAlignment.Center;
fp.Children.Add(g);
Image img = new Image
{
UriSource = imageSource,
};
g.Children.Add(image);
return fp;
}
This is all WPF. I'm creating a FixedPage that has as its root a Grid, which contains an Image that is loaded from the given Uri. The image will be stretched to fill the available space of the Grid. Or, you could do whatever you want. Create a template as a UserControl, send it text to place within itself, whatever.
Next, you just need to add a bunch of fixed pages to an XpsDocument. It's incredibly hard, so read carefully:
public void WriteAllPages(XpsDocument document, IEnumerable<FixedPage> pages)
{
var writer = XpsDocument.CreateXpsDocumentWriter(document);
foreach(var page in pages)
writer.Write(page);
}
And that's all you need to do. Create your pages, add them to your document. Done.

Making self-extracting executable with C#

I'm creating simple self-extracting archive using magic number to mark the beginning of the content.
For now it is a textfile:
MAGICNUMBER .... content of the text file
Next, textfile copied to the end of the executable:
copy programm.exe/b+textfile.txt/b sfx.exe
I'm trying to find the second occurrence of the magic number (the first one would be a hardcoded constant obviously) using the following code:
string my_filename = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
StreamReader file = new StreamReader(my_filename);
const int block_size = 1024;
const string magic = "MAGICNUMBER";
char[] buffer = new Char[block_size];
Int64 count = 0;
Int64 glob_pos = 0;
bool flag = false;
while (file.ReadBlock(buffer, 0, block_size) > 0)
{
var rel_pos = buffer.ToString().IndexOf(magic);
if ((rel_pos > -1) & (!flag))
{
flag = true;
continue;
}
if ((rel_pos > -1) & (flag == true))
{
glob_pos = block_size * count + rel_pos;
break;
}
count++;
}
using (FileStream fs = new FileStream(my_filename, FileMode.Open, FileAccess.Read))
{
byte[] b = new byte[fs.Length - glob_pos];
fs.Seek(glob_pos, SeekOrigin.Begin);
fs.Read(b, 0, (int)(fs.Length - glob_pos));
File.WriteAllBytes("c:/output.txt", b);
but for some reason I'm copying almost entire file, not the last few kilobytes. Is it because of the compiler optimization, inlining magic constant in while loop of something similar?
How should I do self-extraction archive properly?
Guessed I should read file backwards to avoid problems of compiler inlining magic constant multiply times.
So I've modified my code in the following way:
string my_filename = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
StreamReader file = new StreamReader(my_filename);
const int block_size = 1024;
const string magic = "MAGIC";
char[] buffer = new Char[block_size];
Int64 count = 0;
Int64 glob_pos = 0;
while (file.ReadBlock(buffer, 0, block_size) > 0)
{
var rel_pos = buffer.ToString().IndexOf(magic);
if (rel_pos > -1)
{
glob_pos = block_size * count + rel_pos;
}
count++;
}
using (FileStream fs = new FileStream(my_filename, FileMode.Open, FileAccess.Read))
{
byte[] b = new byte[fs.Length - glob_pos];
fs.Seek(glob_pos, SeekOrigin.Begin);
fs.Read(b, 0, (int)(fs.Length - glob_pos));
File.WriteAllBytes("c:/output.txt", b);
}
So I've scanned the all file once, found that I though would be the last occurrence of the magic number and copied from here to the end of it. While the file created by this procedure seems smaller than in previous attempt it in no way the same file I've attached to my "self-extracting" archive. Why?
My guess is that position calculation of the beginning of the attached file is wrong due to used conversion from binary to string. If so how should I modify my position calculation to make it correct?
Also how should I choose magic number then working with real files, pdfs for example? I wont be able to modify pdfs easily to include predefined magic number in it.

Try this out. Some C# Stream IO 101:
public static void Main()
{
String path = #"c:\here is your path";
// Method A: Read all information into a Byte Stream
Byte[] data = System.IO.File.ReadAllBytes(path);
String[] lines = System.IO.File.ReadAllLines(path);
// Method B: Use a stream to do essentially the same thing. (More powerful)
// Using block essentially means 'close when we're done'. See 'using block' or 'IDisposable'.
using (FileStream stream = File.OpenRead(path))
using (StreamReader reader = new StreamReader(stream))
{
// This will read all the data as a single string
String allData = reader.ReadToEnd();
}
String outputPath = #"C:\where I'm writing to";
// Copy from one file-stream to another
using (FileStream inputStream = File.OpenRead(path))
using (FileStream outputStream = File.Create(outputPath))
{
inputStream.CopyTo(outputStream);
// Again, this will close both streams when done.
}
// Copy to an in-memory stream
using (FileStream inputStream = File.OpenRead(path))
using (MemoryStream outputStream = new MemoryStream())
{
inputStream.CopyTo(outputStream);
// Again, this will close both streams when done.
// If you want to hold the data in memory, just don't wrap your
// memory stream in a using block.
}
// Use serialization to store data.
var serializer = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
// We'll serialize a person to the memory stream.
MemoryStream memoryStream = new MemoryStream();
serializer.Serialize(memoryStream, new Person() { Name = "Sam", Age = 20 });
// Now the person is stored in the memory stream (just as easy to write to disk using a
// file stream as well.
// Now lets reset the stream to the beginning:
memoryStream.Seek(0, SeekOrigin.Begin);
// And deserialize the person
Person deserializedPerson = (Person)serializer.Deserialize(memoryStream);
Console.WriteLine(deserializedPerson.Name); // Should print Sam
}
// Mark Serializable stuff as serializable.
// This means that C# will automatically format this to be put in a stream
[Serializable]
class Person
{
public String Name { get; set; }
public Int32 Age { get; set; }
}

The easiest solution is to replace
const string magic = "MAGICNUMBER";
with
static string magic = "magicnumber".ToUpper();
But there are more problems with the whole magic string approach. What is the file contains the magic string? I think that the best solution is to put the file size after the file. The extraction is much easier that way: Read the length from the last bytes and read the required amount of bytes from the end of the file.
Update: This should work unless your files are very big. (You'd need to use a revolving pair of buffers in that case (to read the file in small blocks)):
string inputFilename = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
string outputFilename = inputFilename + ".secret";
string magic = "magic".ToUpper();
byte[] data = File.ReadAllBytes(inputFilename);
byte[] magicData = Encoding.ASCII.GetBytes(magic);
for (int idx = magicData.Length - 1; idx < data.Length; idx++) {
bool found = true;
for (int magicIdx = 0; magicIdx < magicData.Length; magicIdx++) {
if (data[idx - magicData.Length + 1 + magicIdx] != magicData[magicIdx]) {
found = false;
break;
}
}
if (found) {
using (FileStream output = new FileStream(outputFilename, FileMode.Create)) {
output.Write(data, idx + 1, data.Length - idx - 1);
}
}
}
Update2: This should be much faster, use little memory and work on files of all size, but the program your must be proper executable (with size being a multiple of 512 bytes):
string inputFilename = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
string outputFilename = inputFilename + ".secret";
string marker = "magic".ToUpper();
byte[] data = File.ReadAllBytes(inputFilename);
byte[] markerData = Encoding.ASCII.GetBytes(marker);
int markerLength = markerData.Length;
const int blockSize = 512; //important!
using(FileStream input = File.OpenRead(inputFilename)) {
long lastPosition = 0;
byte[] buffer = new byte[blockSize];
while (input.Read(buffer, 0, blockSize) >= markerLength) {
bool found = true;
for (int idx = 0; idx < markerLength; idx++) {
if (buffer[idx] != markerData[idx]) {
found = false;
break;
}
}
if (found) {
input.Position = lastPosition + markerLength;
using (FileStream output = File.OpenWrite(outputFilename)) {
input.CopyTo(output);
}
}
lastPosition = input.Position;
}
}
Read about some approaches here: http://www.strchr.com/creating_self-extracting_executables

You can add the compressed file as resource to the project itself:
Project > Properties
Set the property of this resource to Binary.
You can then retrieve the resource with
byte[] resource = Properties.Resources.NameOfYourResource;

Search backwards rather than forwards (assuming your file won't contain said magic number).
Or append your (text) file and then lastly its length (or the length of the original exe), so you only need read the last DWORD / few bytes to see how long the file is - then no magic number is required.
More robustly, store the file as an additional data section within the executable file. This is more fiddly without external tools as it requires knowledge of the PE file format used for NT executables, q.v. http://msdn.microsoft.com/en-us/library/ms809762.aspx