I have a variable which holds a pdf stream , this variable is of type System.Threading.Tasks.Task<Stream>. I want to save this pdf stream in a pdf file but I am not sure how to do so . Below is a piece of code I tried to work on . Any ideas as to what I can try to save this stream in a file
System.Threading.Tasks.Task<Stream> pdf = //Some logic here which gets a pdf stream
I want to store the pdf content in the variable in a file as a pdf
For that I worote the method
public static void SaveStreamAsFile(string filePath, System.Threading.Tasks.Task<Stream> inputStream, string fileName)
{
string path = Path.Combine(filePath, fileName);
using (FileStream outputFileStream = new FileStream(path, FileMode.Create))
{
// logic
}
}
Read the input stream and write it to the output stream..
public static async Task SaveStreamAsFile(string filePath, System.Threading.Tasks.Task<Stream> inputStream, string fileName)
{
var stream = await inputStream;
var path = Path.Combine(filePath, fileName);
var bytesInStream = new byte[stream.Length];
await stream.ReadAsync(bytesInStream, 0, (int) bytesInStream.Length);
using (var outputFileStream = new FileStream(path, FileMode.Create))
{
await outputFileStream.WriteAsync(bytesInStream, 0, bytesInStream.Length);
}
}
Related
Hi so I'm trying to save an image selected by the user to file so that i can later upload it to my mySQL database.
So I have this code:
var result = await MediaPicker.PickPhotoAsync(new MediaPickerOptions
{
Title = "Please pick a selfie"
});
var stream = await result.OpenReadAsync();
resultImage.Source = ImageSource.FromStream(() => stream);
string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
string filename = Path.Combine(path, "myfile");
using (var streamWriter = new StreamWriter(filename, true))
{
streamWriter.WriteLine(GetImageBytes(stream).ToString());
}
using (var streamReader = new StreamReader(filename))
{
string content = streamReader.ReadToEnd();
System.Diagnostics.Debug.WriteLine(content);
}
Here's the GetImageBytes(..) function:
private byte[] GetImageBytes(Stream stream)
{
byte[] ImageBytes;
using (var memoryStream = new System.IO.MemoryStream())
{
stream.CopyTo(memoryStream);
ImageBytes = memoryStream.ToArray();
}
return ImageBytes;
}
The code kind of works, it creates a file but doesn't save the image. Instead it saves "System.Bytes[]". It saves the name of the object, not the contents of the object.
myfile
enter image description here
Any help would be really appreciated. Thanks!
StreamWriter is for writing formatted strings, not binary data. Try this instead
File.WriteAllBytes(filename,GetImageBytes(stream));
Encode the byte array as a base64 string, then store that in the file:
private string GetImageBytesAsBase64String(Stream stream)
{
var imageBytes;
using (var memoryStream = new System.IO.MemoryStream())
{
stream.CopyTo(memoryStream);
imageBytes = memoryStream.ToArray();
}
return Convert.ToBase64String(imageBytes);
}
If you later need to retrieve the image bytes from the file, you can use the corresponding Convert.FromBase64String(imageBytesAsBase64String) method.
I would like to copy the partial content of a file using FileStream seek.
the actual file stream length of the file = 98764.
I want file content between length 200 and 5000
If I am doing fileStream.Seek(200, SeekOrigin.Begin), then this give me file content from 200 to 98764, but I want from 200 and 5000.
public static async Task<HttpResponseMessage> Get()
{
using (var fileStream = new FileStream(#"C:\test\tes1.txt", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
var actualFileStremSize = fileStream.Length;
//fileStream.Seek(200, SeekOrigin.Begin);
var result = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StreamContent(fileStream),
};
using (FileStream fs = new FileStream(#"C:\test\tes1_partial_copy.txt", FileMode.CreateNew, FileAccess.Write))
{
await result.Content.CopyToAsync(fs);
}
return result;
}
}
}
Main Method,
class Program
{
static void Main(string[] args)
{
Get().Wait();
Console.ReadLine();
}
Looking for a solution to get file content between 2 file stream length. Thanks,
The application i'm developing needs to compress xml files into zip files and send them through http requests to a web service. As I dont need to keep the zip files, i'm just performing the compression in memory. The web service is denying my requests because the zip files are apparently malformed.
I know there is a solution in this question which works perfectly, but it uses a StreamWriter. My problem with that solution is that StreamWriter requires an encoding or assumes UTF-8, and I do not need to know the enconding of the xml files. I just need to read the bytes from those files, and store them inside a zip file, whatever encoding they use.
So, to be clear, this question has nothing to do with encodings, as I don't need to transform the bytes into text or the oposite. I just need to compress a byte[].
I'm using the next code to test how my zip file is malformed:
static void Main(string[] args)
{
Encoding encoding = Encoding.GetEncoding("ISO-8859-1");
string xmlDeclaration = "<?xml version=\"1.0\" encoding=\"" + encoding.WebName.ToUpperInvariant() + "\"?>";
string xmlBody = "<Test>ª!\"·$%/()=?¿\\|##~€¬'¡º</Test>";
string xmlContent = xmlDeclaration + xmlBody;
byte[] bytes = encoding.GetBytes(xmlContent);
string fileName = "test.xml";
string zipPath = #"C:\Users\dgarcia\test.zip";
Test(bytes, fileName, zipPath);
}
static void Test(byte[] bytes, string fileName, string zipPath)
{
byte[] zipBytes;
using (var memoryStream = new MemoryStream())
using (var zipArchive = new ZipArchive(memoryStream, ZipArchiveMode.Create, leaveOpen: false))
{
var zipEntry = zipArchive.CreateEntry(fileName);
using (Stream entryStream = zipEntry.Open())
{
entryStream.Write(bytes, 0, bytes.Length);
}
//Edit: as the accepted answer states, the problem is here, because i'm reading from the memoryStream before disposing the zipArchive.
zipBytes = memoryStream.ToArray();
}
using (var fileStream = new FileStream(zipPath, FileMode.OpenOrCreate))
{
fileStream.Write(zipBytes, 0, zipBytes.Length);
}
}
If I try to open that file, I get an "Unexpected end of file" error. So apparently, the web service is correctly reporting a malformed zip file. What I have tried so far:
Flushing the entryStream.
Closing the entryStream.
Both flushing and closing the entryStream.
Note that if I open the zipArchive directly from the fileStream the zip file is formed with no errors. However, the fileStream is just there as a test, and I need to create my zip file in memory.
You are trying to get bytes from MemoryStream too early, ZipArchive did not write them all yet. Instead, do like this:
using (var memoryStream = new MemoryStream()) {
// note "leaveOpen" true, to not dispose memoryStream too early
using (var zipArchive = new ZipArchive(memoryStream, ZipArchiveMode.Create, leaveOpen: true)) {
var zipEntry = zipArchive.CreateEntry(fileName);
using (Stream entryStream = zipEntry.Open()) {
entryStream.Write(bytes, 0, bytes.Length);
}
}
// now, after zipArchive is disposed - all is written to memory stream
zipBytes = memoryStream.ToArray();
}
If you use a memory stream to load your text you can control the encoding type and it works across a WCF service. This is the implementation i am using currently and it works on my WCF services
private byte[] Zip(string text)
{
var bytes = Encoding.UTF8.GetBytes(text);
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream())
{
using (var gs = new GZipStream(mso, CompressionMode.Compress))
{
CopyTo(msi, gs);
}
return mso.ToArray();
}
}
private string Unzip(byte[] bytes)
{
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream())
{
using (var gs = new GZipStream(msi, CompressionMode.Decompress))
{
CopyTo(gs, mso);
}
return Encoding.UTF8.GetString(mso.ToArray());
}
}
I have a JSON file created, and I am going to zip it using DotNetZip.
Using with StreamWriter to zip it is working, if I try to use MemoryStream it will not working.
StreamWriter :
sw = new StreamWriter(assetsFolder + #"manifest.json");
sw.Write(strManifest);
sw.Close();
zip.AddFile(Path.Combine(assetsFolder, "manifest.json"), "/");
zip.AddFile(Path.Combine(assetsFolder, "XXXXXXX"), "/");
zip.Save(outputStream);
MemoryStream :
var manifestStream = GenerateStreamFromString(strManifest);
public static Stream GenerateStreamFromString(string s)
{
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(s);
writer.Flush();
stream.Position = 0;
return stream;
}
zip.AddEntry("manifest.json", manifestStream);
zip.AddFile(Path.Combine(assetsFolder, "XXXXXXX"), "/");
zip.Save(outputStream);
I must using the .JSON file type to zip it, Can any one told me where have a mistake?
To create a Gzipped Json you need to use GZipStream. Try method below.
https://www.dotnetperls.com/gzipstream
GZipStream compresses data. It saves data efficiently—such as in
compressed log files. We develop a utility method in the C# language
that uses the System.IO.Compression namespace. It creates GZIP files.
It writes them to the disk.
public static void CompressStringToFile(string fileName, string value)
{
// A.
// Write string to temporary file.
string temp = Path.GetTempFileName();
File.WriteAllText(temp, value);
// B.
// Read file into byte array buffer.
byte[] b;
using (FileStream f = new FileStream(temp, FileMode.Open))
{
b = new byte[f.Length];
f.Read(b, 0, (int)f.Length);
}
// C.
// Use GZipStream to write compressed bytes to target file.
using (FileStream f2 = new FileStream(fileName, FileMode.Create))
using (GZipStream gz = new GZipStream(f2, CompressionMode.Compress, false))
{
gz.Write(b, 0, b.Length);
}
}
I want to copy a file from one folder to another folder using filestream.How this can be achived.when I try to use file.copy I was getting this file is using by another process, to avoid this I want to use file stream using c#. Can some one provide a sample for copying a file from one folder to another.
for copying i used below code :-
public static void Copy(string inputFilePath, string outputFilePath)
{
int bufferSize = 1024 * 1024;
using (FileStream fileStream = new FileStream(outputFilePath, FileMode.OpenOrCreate, FileAccess.Write,FileShare.ReadWrite))
//using (FileStream fs = File.Open(<file-path>, FileMode.Open, FileAccess.Read, FileShare.Read))
{
FileStream fs = new FileStream(inputFilePath, FileMode.Open, FileAccess.ReadWrite);
fileStream.SetLength(fs.Length);
int bytesRead = -1;
byte[] bytes = new byte[bufferSize];
while ((bytesRead = fs.Read(bytes, 0, bufferSize)) > 0)
{
fileStream.Write(bytes, 0, bytesRead);
}
}
}
You can use Stream.CopyTo method to copy the file like below:
public static string CopyFileStream(string outputDirectory, string inputFilePath)
{
FileInfo inputFile = new FileInfo(inputFilePath);
using (FileStream originalFileStream = inputFile.OpenRead())
{
var fileName = Path.GetFileName(inputFile.FullName);
var outputFileName = Path.Combine(outputDirectory, fileName);
using (FileStream outputFileStream = File.Create(outputFileName))
{
originalFileStream.CopyTo(outputFileStream);
}
return outputFileName;
}
}
string fileName = "Mytest.txt";
string sourcePath = #"C:\MyTestPath";
string targetPath = #"C:\MyTestTarget";
string sourceFile = System.IO.Path.Combine(sourcePath, fileName);
string destFile = System.IO.Path.Combine(targetPath, fileName);
{
System.IO.Directory.CreateDirectory(targetPath);
}
// To copy a file to another location and
// overwrite the destination file if it already exists.
System.IO.File.Copy(sourceFile, destFile, true);