I'm trying to write a decompression mechanism for a Web API MessageHandler. However, despite a little research I can't seem to make this work :-(
The problem is reproducible with the following test:
[Test]
public void Deflate()
{
using (var outStream = new MemoryStream())
{
using (var compressionStream = new DeflateStream(outStream, CompressionMode.Compress, true))
{
using (var original = new MemoryStream(Encoding.UTF8.GetBytes("original content")))
{
original.CopyTo(compressionStream);
}
}
//this passes
Assert.IsTrue(outStream.Length > 0);
var compressedStream = outStream;
var decompressionResultStream = compressedStream.DeflateDecompressor();
//this fails
Assert.IsTrue(decompressionResultStream.Length > 0);
var output = Encoding.UTF8.GetString(decompressionResultStream.ToArray());
Assert.AreEqual("original content", output);
}
}
and the following Decompression Handler
public static class DecompressionHandlers
{
public static MemoryStream DeflateDecompressor(this Stream compressedStream)
{
var decompressionResultStream = new MemoryStream();
using (var decompressionStream = new DeflateStream(compressedStream, CompressionMode.Decompress, true))
{
decompressionStream.CopyTo(decompressionResultStream);
decompressionStream.Flush();
}
return decompressionResultStream;
}
public static MemoryStream GZipDecompressor(this Stream compressedStream)
{
var decompressionResultStream = new MemoryStream();
using (var decompressionStream = new GzipStream(compressedStream, CompressionMode.Decompress, true))
{
decompressionStream.CopyTo(decompressionResultStream);
decompressionStream.Flush();
}
return decompressionResultStream;
}
}
Hopefully, this is a straight ID-ten-T problem and any advice is gratefully received!
That this is to be used in a Web API MessageHandler may well be a red herring but is included for completeness
In your code, try resetting the position of the compressedStream before you invoke decompression on it.
compressedStream.Position = 0;
var decompressionResultStream = compressedStream.DeflateDecompressor();
Note that you seem to be using DeflateStream instead of GZipStream in your GZipDecompressor method.
Related
I know that NAudio.UWP is a work in progress but the newest release (1.8) does seem to have the ability to write a .wav.
private IWavePlayer player;
private WaveStream reader;
private IWaveIn recorder;
private MemoryStream recordStream;
private IRandomAccessStream selectedStream;
private void Record()
{
if (recorder == null)
{
recorder = new WasapiCaptureRT();
recorder.RecordingStopped += RecorderOnRecordingStopped;
recorder.DataAvailable += RecorderOnDataAvailable;
}
if (reader != null)
{
reader.Dispose();
reader = null;
}
recorder.StartRecording();
}
private async void RecorderOnDataAvailable(object sender, WaveInEventArgs waveInEventArgs)
{
Debug.WriteLine(waveInEventArgs.BytesRecorded);
if (reader == null)
{
recordStream = new MemoryStream();
reader = new RawSourceWaveStream(recordStream, recorder.WaveFormat);
}
await recordStream.WriteAsync(waveInEventArgs.Buffer, 0, waveInEventArgs.BytesRecorded);
}
Where/How do you create the Storage file name, path etc? There is no destination param...This is the only code that came with the example.
**Mark if you see this Chrome is blocking the 1.8 code download.
Where/How do you create the Storage file name, path etc?
It actually depends on your requirements. For example, you could use fixed name and timestamp to named your audio file.
var file = KnownFolders.MusicLibrary.CreateFileAsync("song"+DateTime.Now.ToString("yyyy-MM-DD-hh-mm-ss")+".wav",CreationCollisionOption.GenerateUniqueName);
You could copy record stream to a new file stream. For example:
var file = await KnownFolders.MusicLibrary.CreateFileAsync("test.wav");
using (var stream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
recordStream.CopyTo(stream.AsStream());
}
I'm new to Xamarin. I'm trying display a list of downloaded images. I am downloading images from an APP API on Azure, where I stored the file on Azure Storage.
My server code is the following:
public HttpResponseMessage Get(string PK, string RK)
{
//Creating CloudBlockBlolb...
byte[] bytes = new byte[blockBlob.Properties.Length]
for(int i = 0; i < blockBlob.Properties.Length; i++){
bytes[i] = 0x20;
}
blockBlob.DownloadToByteArray(bytes, 0);
HttpResponseMessage resp = new HttpResponseMessage(HttpStatusCode.OK);
resp.Content = new ByteArrayContent(bytes);
resp.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/jpg");
return resp;
}
My Xamarin code is the following:
public MainPage ()
{
//...
List<PicturePost> list = new List<PicturePost>{
new PicturePost("title", "subtitle", "link/api/Pictures?PK=xxx&RK=yyy")
};
InitializeComponent ();
listView.ItemTemplate = new DataTemplate (typeof(CustomImageCell));
listView.HasUnevenRows = true;
listView.ItemsSource = list;
//...
}
And here is the relevant code for CustomImageCell:
var image = new Image ();
image.SetBinding (Image.SourceProperty, "image");
//...
horizontalLayout.Children.Add (image);
I know that my API call works, because when I test it on the browser, it returns the image. I also know that if I use any random links such as http://www.natureasia.com/common/img/splash/thailand.jpg the image is downloaded and displayed properly. It is only when I use the API link that it doesn't seem to be working. Can someone tell me what I am doing wrong?
so in my public MainPage(), I added the following:
listView.BeginRefresh ();
listView.EndRefresh ();
I realized at some point that the images would take some time to download. I assume that when the listView was created, the images were not finished downloading, so I added the code above... Pretty sure this is not the best way to do this (probably an await would be better, but I don't know where).
Here I coding for get each and every StudyUID(as string) from database to SqlDataReader,but i need to know how the reader value call to forloop execution.
Get to read each and every StudyUID for execution.Here is the code :.
public void automaticreport()
{
//string autsdyid="";
SqlConnection con = new SqlConnection(constr);
con.Open();
string autoquery = "Select StudyUID From StudyTable Where status='2'";
SqlCommand cmd = new SqlCommand(autoquery, con);
SqlDataReader rdr = cmd.ExecuteReader();
for()
{
//how to call each StudyUId from database through for loop
if (!this.reportchk)
{
Reportnew cf = new Reportnew();
ThreadPool.QueueUserWorkItem((WaitCallback)(o => cf.ReportRetrive(this, autsdyid, true)));
}
else
{
int num = (int)System.Windows.Forms.MessageBox.Show("Reports checking in progress, Please wait sometime and try again later", "OPTICS", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
con.Close();
}
Like #R.T and others have mentioned you can use the Read method on the data reader. Looking at your sample code you might want to refactor it slightly to meet more of the SOLID principles and make sure you're not leaking database connections
Here's an example of code that has been refactored a bit.
public void automaticreport()
{
foreach (var autsdyid in LoadStudyIdentifiers())
{
if (!this.reportchk)
{
Reportnew cf = new Reportnew();
ThreadPool.QueueUserWorkItem((WaitCallback)(o => cf.ReportRetrive(this, autsdyid, true)));
}
else
{
int num = (int)System.Windows.Forms.MessageBox.Show("Reports checking in progress, Please wait sometime and try again later", "OPTICS", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
}
}
private string[] LoadStudyIdentifiers()
{
var results = new List<string>();
// adding a using statement will close the database connection if there are any errors
// avoiding consuming the database connection pool
using (var con = new SqlConnection(constr))
{
conn.Open();
var autoquery = "Select StudyUID From StudyTable Where status='2'";
using (var cmd = new SqlCommand(autoquery, con))
{
SqlDataReader rdr = cmd.ExecuteReader();
while(rdr.Read())
{
results.Add(rdr.GetString(rdr.GetOrdinal("StudyUID")));
}
}
}
return results.ToArray();
}
Note: I wrote this in notepad so there is no guarantee it will compile but should give an indication as to how you could refactor your code.
if (rdr.HasRows)
{
while (rdr.Read())
{
Console.WriteLine(rdr.getString("columnName"));
}
}
You can use something like:
while (reader.Read())
{
string value = reader.getString("columnName");
}
You may use the while loop like this:
while (rdr.Read())
{
string s = rdr.GetString(rdr.GetOrdinal("Column"));
//Apply logic to retrieve here
}
I want to post some request values alongside the multipart-formdata file contents. In the old API you could use PostFileWithRequest:
[Test]
public void Can_POST_upload_file_using_ServiceClient_with_request()
{
IServiceClient client = new JsonServiceClient(ListeningOn);
var uploadFile = new FileInfo("~/TestExistingDir/upload.html".MapProjectPath());
var request = new FileUpload{CustomerId = 123, CustomerName = "Foo"};
var response = client.PostFileWithRequest<FileUploadResponse>(ListeningOn + "/fileuploads", uploadFile, request);
var expectedContents = new StreamReader(uploadFile.OpenRead()).ReadToEnd();
Assert.That(response.FileName, Is.EqualTo(uploadFile.Name));
Assert.That(response.ContentLength, Is.EqualTo(uploadFile.Length));
Assert.That(response.Contents, Is.EqualTo(expectedContents));
Assert.That(response.CustomerName, Is.EqualTo("Foo"));
Assert.That(response.CustomerId, Is.EqualTo(123));
}
I can't find any such method in the new API, nor any overrides on client.Post() which suggest that this is still possible. Does anyone know if this is a feature that was dropped?
Update
As #Mythz points out, the feature wasn't dropped. I had made the mistake of not casting the client:
private IRestClient CreateRestClient()
{
return new JsonServiceClient(WebServiceHostUrl);
}
[Test]
public void Can_WebRequest_POST_upload_binary_file_to_save_new_file()
{
var restClient = (JsonServiceClient)CreateRestClient(); // this cast was missing
var fileToUpload = new FileInfo(#"D:/test/test.avi");
var beforeHash = this.Hash(fileToUpload);
var response = restClient.PostFileWithRequest<FilesResponse>("files/UploadedFiles/", fileToUpload, new TestRequest() { Echo = "Test"});
var uploadedFile = new FileInfo(FilesRootDir + "UploadedFiles/test.avi");
var afterHash = this.Hash(uploadedFile);
Assert.That(beforeHas, Is.EqualTo(afterHash));
}
private string Hash(FileInfo file)
{
using (var md5 = MD5.Create())
{
using (var stream = file.OpenRead())
{
var bytes = md5.ComputeHash(stream);
return BitConverter.ToString(md5.ComputeHash(stream)).Replace("-", "").ToLower();
}
}
}
None of the old API was removed from the C# Service Clients, only new API's were added.
The way you process an uploaded file inside a service also hasn't changed.
I have four MemoryStreams of data that I want to merge and then open the pdfDocument, without creating a single file.
It's possible to write them down to files and then merge them but that would be bad practice and that can also cause a few issues so I want to avoid that.
However, I can not find a way to merge the MemoryStreams with iText5 for .NET.
Right now, this is how I do it with files:
private static void ConcatenateDocuments()
{
var stream = new MemoryStream();
var readerFrontPage = new PdfReader(Folder + FrontPageName);
var readerDocA = new PdfReader(Folder + docA);
var readerDocB = new PdfReader(Folder + DocB);
var readerAppendix = new PdfReader(Folder + Appendix);
var pdfCopyFields = new PdfCopyFields(stream);
pdfCopyFields.AddDocument(readerFrontPage);
pdfCopyFields.AddDocument(readerDocA );
pdfCopyFields.AddDocument(readerDocB);
pdfCopyFields.AddDocument(readerAppendix);
pdfCopyFields.Close();
SavePdf(stream, FilenameReport);
}
Since I need to remove the use of files, I keep the MemoryStream's as the different parts are built from different resources. So I have references to these memorystreams.
How can this be done?
The error PDF header signature not found can be fixed in this case by setting the stream's Position back to 0. Since you're not getting the error Cannot access a closed Stream I'm assuming that you are already correctly setting the PdfWriter's CloseStream to false.
Below is a full working C# 2010 WinForm app targeting iTextSharp 5.1.1.0 that creates three PDFs in MemoryStreams and combines them. Since I don't have a web server handy I'm writing them to disk.
using System;
using System.Text;
using System.Windows.Forms;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
//Create three MemoryStreams
MemoryStream[] streams = { CreateDoc("Page 1"), CreateDoc("Page 2"), CreateDoc("Page 3") };
//I don't have a web server handy so I'm going to write my final MemoryStream to a byte array and then to disk
byte[] bytes;
//Create our final combined MemoryStream
using (MemoryStream finalStream = new MemoryStream())
{
//Create our copy object
PdfCopyFields copy = new PdfCopyFields(finalStream);
//Loop through each MemoryStream
foreach (MemoryStream ms in streams)
{
//Reset the position back to zero
ms.Position = 0;
//Add it to the copy object
copy.AddDocument(new PdfReader(ms));
//Clean up
ms.Dispose();
}
//Close the copy object
copy.Close();
//Get the raw bytes to save to disk
bytes = finalStream.ToArray();
}
//Write out the file to the desktop
string outputFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Combined.pdf");
using (FileStream fs = new FileStream(outputFile, FileMode.Create, FileAccess.Write, FileShare.None))
{
fs.Write(bytes, 0, bytes.Length);
}
this.Close();
}
/// <summary>
/// Helper method to create temporary documents
/// </summary>
private MemoryStream CreateDoc(string name)
{
MemoryStream ms = new MemoryStream();
using (Document doc = new Document(PageSize.LETTER))
{
using (PdfWriter writer = PdfWriter.GetInstance(doc, ms))
{
writer.CloseStream = false;
doc.Open();
doc.Add(new Paragraph(name));
doc.Close();
}
}
return ms;
}
}
}
While it seams the PdfReader can not take the stream, the array of the stream works.
var readerFrontPage = new PdfReader(streamFrontPage.ToArray());