WebClient Class

I have a device application project and I am getting this error.

I am using VB code in Symbol terminal with WINCE 5.0 and using compact framework 2.0
It does not allow me to use webclient to download a picture from a server from http site.

There is any classe that we can use in compact netframework 2.0 and wince ?

Thanks,

What is the difference between this class and HttpWebRequest class?

[tfl - 22 10 09] Hi - and thanks for your post. You should post questions like this to the MSDN Forums at http://forums.microsoft.com/msdn or the MSDN Newsgroups at 

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The example also fails to dispose the stream returned by the OpenRead method. Also, the example is sort of strange in that it employs an arbitrary UserAgent.

Here's a better example:

  using (WebClient client = new WebClient ())
  {

    using (System.IO.Stream s = client.OpenRead(uri) )
    {
      byte[] bytes = s.ReadAllBytes();
      // do your thing...
    }
  }

But that is a bit contrived. If you want to get all the bytes from a URI, you would use the WebClient.DownloadData() method, like so:

  using (WebClient client = new WebClient ())
  {

      byte[] bytes = client.DownloadData(uri);
      // do your thing...
    }
  }

Also be aware: The alternative contrived example code provided here employs an extension method, ReadAllBytes, on the Stream class, defined like so:

    public static class Extensions
    {
        /// <summary>   
        /// Reads the contents of the stream into a byte array.   
        /// data is returned as a byte array. An IOException is   
        /// thrown if any of the underlying IO calls fail.   
        /// </summary>   
        /// <param name="stream">The stream to read.</param>   
        /// <returns>A byte array containing the contents of the stream.</returns>   
        /// <exception cref="NotSupportedException">The stream does not support reading.</exception>   
        /// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>  
        /// <exception cref="System.IO.IOException">An I/O error occurs.</exception>  
        public static byte[] ReadAllBytes(this System.IO.Stream source)
        {  
            long originalPosition = 0;
            if (source.CanSeek)
            {
                originalPosition= source.Position;  
                source.Position = 0;  
            }

            try  
            {  
                byte[] readBuffer = new byte[4096];  

                int totalBytesRead = 0;  
                int bytesRead;  

                while ((bytesRead = source.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)  
                {  
                    totalBytesRead += bytesRead;  

                    if (totalBytesRead == readBuffer.Length)  
                    {  
                        int nextByte = source.ReadByte();  
                        if (nextByte != -1)  
                        {  
                            byte[] temp = new byte[readBuffer.Length * 2];  
                            Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);  
                            Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);  
                            readBuffer = temp;  
                            totalBytesRead++;  
                        }  
                    }  
                }  

                byte[] buffer = readBuffer;  
                if (readBuffer.Length != totalBytesRead)  
                {  
                    buffer = new byte[totalBytesRead];  
                    Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);  
                }  
                return buffer;  
            }  
            finally  
            {  
                if (source.CanSeek)
                    source.Position = originalPosition;  
            }  
        }    
    }

This extension is taken, slightly modified, from


http://www.lostechies.com/blogs/sdorman/archive/2009/01/10/reading-all-bytes-from-a-stream.aspx

The WebClient class inherits the IDisposable interface and should therefore be disposed properly. If you are using C#, then use the using statement like this:
using(WebClient client = new WebClient()) {
// Do your thing
}