As a follow-up on my previous post about pulling data from a web site, this post is about doing it the other way -- uploading data to a web site.

Let's first fill a byte array with some content, usually from a file (or database) like this (require a reference to System.IO)...

FileStream fs = File.OpenRead("file.any");
BinaryReader br = new BinaryReader(fs);
byte[] data = br.ReadBytes((int)br.BaseStream.Length);
br.Close();
fs.Close();

...and then the code to upload looks like this (require an additional reference to System.Net)...

string url = "http://www.businessanyplace.net/file.any";
Uri uri = new Uri(url);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);
request.Method = "PUT";
request.Credentials = new NetworkCredential("UserName", "P@ssW0rd");
request.PreAuthenticate = true;
request.AllowWriteStreamBuffering = true;
// For large files (> 50KB) you may want to uncomment the next line
//request.SendChunked = true;
request.ContentLength = data.Length;
Stream s = request.GetRequestStream();
s.Write(data, 0, data.Length);
s.Close();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
HttpStatusCode code = response.StatusCode;
string result = code.ToString();

...and this works just as well for text files as for any binary file. Please note that the user needs to have write access to the virtual directory (and the physical disk location) where the file is to be written. For a more complete example of how files (media) can be compressed (zipped) and uploaded to a Web site, see the source code for my article Claims2Go: Claims Processing for Windows Mobile-Based Devices.

There are some questions that seem to be coming back all the time, and one of those is how to download from a web site. Whether it's a file or an image, it's basically the same approach.

I saw a nice article on DevSource name Pulling Data From Internet URLs in C# using the WebClient class which is a good alternative if you are planning on using it in the upcoming Compact Framework 3.5. But if you want a solution now, here's some code. Let's start by downloading a file (references to System.Net and System.IO)...

string url = "http://www.businessanyplace.net/images/ba.gif";
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(new Uri(url));
request.Credentials = new NetworkCredential("UserName", "P@ssW0rd");
request.PreAuthenticate = true;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
int size = 2048;
byte[] data = new byte[size];
FileStream fs = File.Create("baOnDisk.gif");
while(true)
{
    size = s.Read(data, 0, data.Length);
    if(size > 0)
        fs.Write(data, 0, size);
    else
        break;
}
fs.Close();

...and note that the download is buffered (in 2K blocks). I've also added some credential code to make it more realistic. If you want the contents of a text file in a string, the code can be modified like this (with a reference to System.Text)...

string url = "http://www.businessanyplace.net/sample/test.htm";
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(new Uri(url));
request.Credentials = new NetworkCredential("UserName", "P@ssW0rd");
request.PreAuthenticate = true;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
StringBuilder sb = new StringBuilder();
int size = 2048;
byte[] data = new byte[size];
while(true)
{
    size = s.Read(data, 0, data.Length);
    if(size > 0)
        sb.Append(Encoding.ASCII.GetString(data, 0, size));
    else
        break;
}
string strData = sb.ToString();

...and to process that further (parsing the HTML, etc), you can now follow the same approach described in the article mentioned above.