A simple example of using httphandler in ASP.NET 2.0

Let's started by creating a new web application in Visual Studio 2008 Team Suite.

Step 1:
create a class named PhotoManager to manage our photoes. In this class, we store the binary data in a memory stream no matter what the binary data comes from. (It may be from the database, or we create the image at real time, etc..)

 1public class PhotoManager
 2{
 3    public static Stream GetPhoto()
 4    {
 5        String strDisplay = "Microsoft.com";
 6        Bitmap bmp = new Bitmap(200, 50);
 7
 8        Graphics g = Graphics.FromImage(bmp);
 9        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
10        g.FillRectangle(Brushes.Black, 0, 0, 200, 50);
11        g.DrawString(strDisplay, new Font("verdana", 18), new SolidBrush(Color.White), 0, 0);
12
13        MemoryStream ms = new MemoryStream();
14        bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
15        byte[] bmpBytes = ms.GetBuffer();
16        bmp.Dispose();
17        ms.Close();
18
19        return new MemoryStream(bmpBytes);
20    }
21}

Step 2: Add a generic handler named MyHandler.ashx to the application. This handler will write the stream into our httpcontext.

 1public class MyHandler : IHttpHandler
 2{
 3
 4    public void ProcessRequest(HttpContext context)
 5    {
 6        Stream stream = null;
 7        stream = PhotoManager.GetPhoto();
 8
 9        const int buffersize = 1024 * 16;
10        byte[] buffer = new byte[buffersize];
11        int count = stream.Read(buffer, 0, buffersize);
12
13        while (count > 0)
14        {
15            context.Response.OutputStream.Write(buffer, 0, count);
16            count = stream.Read(buffer, 0, buffersize);
17        }
18    }
19
20    public bool IsReusable
21    {
22        get
23        {
24            return true;
25        }
26    }
27}

Step 3: Use our images in the .aspx file and display it.

<img src="MyHandler.ashx" style="border:solid 4px white" alt="Photo from handler" />

The Result:

Happy coding!!