title: Download generated bitmap image from ASP.NET website
body: <p>I'm dynamically generating image from text, and existing image on my asp.net website.</p>
  
  <p>Here is the code:</p>
  
  <pre><code>string barcode = Request.QueryString["BarCode"];
  int w = barcode.Length * 40;
  
  // Create a bitmap object of the width that we calculated and height of 100
  Bitmap oBitmap = new Bitmap(w, 50);
  
  // then create a Graphic object for the bitmap we just created.
  Graphics oGraphics = Graphics.FromImage(oBitmap);
  
  // Now create a Font object for the Barcode Font
  // (in this case the IDAutomationHC39M) of 18 point size
  Font oFont = new Font("BarcodeFont", 12);
  
  // Let's create the Point and Brushes for the barcode
  PointF oPoint = new PointF(2f, 2f);
  SolidBrush oBrushWrite = new SolidBrush(Color.Black);
  SolidBrush oBrush = new SolidBrush(Color.White);
  
  // Now lets create the actual barcode image
  // with a rectangle filled with white color
  oGraphics.FillRectangle(oBrush, 0, 0, w, 100);
  
  // We have to put prefix and sufix of an asterisk (*),
  // in order to be a valid barcode
  oGraphics.DrawString(barcode, oFont, oBrushWrite, oPoint);
  
  // Then we send the Graphics with the actual barcode
  Response.ContentType = "image/png";
  oBitmap.Save(Response.OutputStream, ImageFormat.Png);
  </code></pre>
  
  <p>As you can see the bitmap is saved and showed on aspx page after postback. What I wanna do is when user click Button1, then image is generated and browser download window pops up, without saving on server or showing on page. How to do this? Please help me.</p>