Initially Declare a generic Handler like this
public class Handler1 : IHttpHandler
{
#region
IHttpHandler Members
private HttpContext _context;
private HttpContext Context
{
get
{
return _context;
}
set
{
_context = value;
}
}
public void ProcessRequest(HttpContext context)
{
Context = context;
string filePath = context.Request.QueryString["path"];
filePath =
context.Server.MapPath(filePath);
if (filePath == null)
{
return;
}
System.IO.StreamReader
streamReader = new System.IO.StreamReader(filePath);
System.IO.BinaryReader br = new System.IO.BinaryReader(streamReader.BaseStream);
byte[] bytes = new byte[streamReader.BaseStream.Length];
br.Read(bytes, 0, (int)streamReader.BaseStream.Length);
if (bytes == null)
{
return;
}
streamReader.Close();
br.Close();
string extension = System.IO.Path.GetExtension(filePath);
string
fileName = System.IO.Path.GetFileName(filePath);
WriteFile(bytes, fileName, "application/" +
extension, context.Response);
}
/// <summary>
/// Sends a byte array to the client
/// </summary>
/// <param name="content">binary file content</param>
/// <param
name="fileName">the filename to be
sent to the client</param>
/// <param
name="contentType">the file content
type</param>
private void WriteFile(byte[] content, string fileName, string contentType, HttpResponse response)
{
response.Buffer = true;
response.Clear();
response.ContentType = contentType;
response.AddHeader("content-disposition", "attachment; filename=" + fileName);
response.BinaryWrite(content);
response.Flush();
response.End();
}
public bool IsReusable
{
get
{
return false;
}
}
#endregion
}
}
Next declare an iframe in aspx page (design)
<iframe id="iframe1 " style="display: none" runat="server" ></iframe>
and an update panel
<asp:UpdatePanel ID="UpdatePanel1 " runat="server" UpdateMode="Conditional">
<ContentTemplate>
//controls design goes here
//Lets assusme we have a GridView1 here
</ContentTemplate>
</asp:UpdatePanel>
Next in aspx codebehind file write code as follows:
Some EventHandler()
{
//Method to bind GridView1 data
UpdatePanel1.Update();
string path="Handler1.ashx?path=" + "declare your path here";
iframe1.Attributes["src"] = path;
}
We are done:
Now we can see the page is partially refreshed when we
called that event.
