Re: [DOTNET] Downloading a binary file using HttpWebResponse

[Sean Greer (SBI-Chico)]

Here's my stab at this problem...this is off the top of my head and has not
been thoroughly tested, but it does work against my pseudo web service. :-)
YMMV

byte[] arrBuffer = new byte[0];
using(BinaryReader reader = new
BinaryReader(webResponse.GetResponseStream()))
{
        byte[] arrScratch = null;
        while((arrScratch = reader.ReadBytes(4096)).Length > 0)
        {
                if(arrBuffer.Length == 0)
                        arrBuffer = arrScratch;
                else
                {
                        byte[] arrTemp = new byte[arrBuffer.Length +
arrScratch.Length];
                        Array.Copy(arrBuffer, arrTemp, arrBuffer.Length);
                        Array.Copy(arrScratch, 0, arrTemp, arrBuffer.Length,
arrScratch.Length);
                        arrBuffer = arrTemp;
                }
        }
}
// use arrBuffer now...

HTH,

Seang

-----Original Message-----
From: Erick Thompson [mailto:[EMAIL PROTECTED]]
Sent: Friday, May 03, 2002 2:24 PM
To: [EMAIL PROTECTED]
Subject: [DOTNET] Downloading a binary file using HttpWebResponse


I'm downloading binary files from the Stream returned by a HttpWebResponse
object. The stream returned does not support seeking or look aheads. I have
no idea when the length of the stream will be (HttpWebResponse.ContentLength
cannot be trusted). What is the fastest way to get the stream into an array
of bytes?

Below is the code that I'm using right now. It does work, but it's slow and
memory intensive (due to the ArrayList and the cast to a byte array). There
must be a better way.

Thanks,
Erick

private void LoadBinaryContent(HttpWebResponse res) {
    Stream binStream = res.GetResponseStream();
    BinaryReader reader = new BinaryReader(binStream);
    int len = (int)res.ContentLength;
    if (len == 0) {
        len = 100000; // make a guess
    }
    ArrayList tmp = new ArrayList(len);
    try {
        while (true) {
            tmp.Add(reader.ReadByte());
        }
    } catch (EndOfStreamException) {
        byte b = 0;
        _binaryContent = (byte[])tmp.ToArray(b.GetType());
    }
    reader.Close();
    binStream.Close();
}

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