Question

Why am I missing bytes when reading from a WebClient stream as follows?

const int chuckDim = 80;

System.Net.WebClient client = new System.Net.WebClient();
Stream stream = client.OpenRead("http://media-cdn.tripadvisor.com/media/photo-s/01/70/3e/a9/needed-backup-lol.jpg");
//Stream stream = client.OpenRead("file:///C:/Users/Tanganello/Downloads/needed-backup-lol.jpg");

//searching file length
WebHeaderCollection whc = client.ResponseHeaders;
int totalLength = (Int32.Parse(whc["Content-Length"]));
byte[] buffer = new byte[totalLength];

//reading and writing
FileStream filestream = new FileStream("C:\\Users\\Tanganello\\Downloads\\clone1.jpg", FileMode.Create, FileAccess.ReadWrite);
int accumulator = 0;
while (accumulator + chuckDim < totalLength) {
    stream.Read(buffer, accumulator, chuckDim);
    filestream.Write(buffer, accumulator, chuckDim);

    accumulator += chuckDim;
}
stream.Read(buffer, accumulator, totalLength - accumulator);
filestream.Write(buffer, accumulator, totalLength - accumulator);

stream.Close();
filestream.Flush();
filestream.Close();

this is what I get with the first stream:
http://img839.imageshack.us/img839/830/clone1h.jpg

Answer 1

The problem is that you are ignoring the return value of the Stream.Read Method:

count

The maximum number of bytes to be read from the current stream.

Return Value

The total number of bytes read into the buffer. This can be less than the number of bytes requested

---

You can avoid the whole business of reading and writing streams by simply using the WebClient.DownloadFile Method:

using (var client = new WebClient())
{
    client.DownloadFile(
        "http://media-cdn.tripadvisor.com/media/photo-s/01/70/3e/a9/needed-backup-lol.jpg",
        "C:\\Users\\Tanganello\\Downloads\\clone1.jpg");
}

Alternatively, if you really want to use streams, you can simply use the Stream.CopyTo Method:

using (var client = new WebClient())
using (var stream = client.OpenRead("http://..."))
using (var file = File.OpenWrite("C:\\..."))
{
    stream.CopyTo(file);
}

If you insist on really copying the bytes yourself, the correct way to do this would be as follows:

using (var client = new WebClient())
using (var stream = client.OpenRead("http://..."))
using (var file = File.OpenWrite("C:\\..."))
{
    var buffer = new byte[512];
    int bytesReceived;
    while ((bytesReceived = stream.Read(buffer, 0, buffer.Length)) != 0)
    {
        file.Write(buffer, 0, bytesReceived);
    }
}