After a user clicks a button, I want a file to be downloaded. I've tried the following which seems to work, but not without throwing an exception (ThreadAbort) which is not acceptable.
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "text/plain";
response.AddHeader("Content-Disposition", "attachment; filename=" + fileName + ";");
response.TransmitFile(Server.MapPath("FileDownload.csv"));
response.Flush();
response.End();
You can use an HTTP Handler (.ashx) to download a file, like this:
DownloadFile.ashx:
public class DownloadFile : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "text/plain";
response.AddHeader("Content-Disposition",
"attachment; filename=" + fileName + ";");
response.TransmitFile(Server.MapPath("FileDownload.csv"));
response.Flush();
response.End();
}
public bool IsReusable
{
get
{
return false;
}
}
}
Then you can call the HTTP Handler from the button click event handler, like this:
Markup:
<asp:Button ID="btnDownload" runat="server" Text="Download File"
OnClick="btnDownload_Click"/>
Code-Behind:
protected void btnDownload_Click(object sender, EventArgs e)
{
Response.Redirect("PathToHttpHandler/DownloadFile.ashx");
}
Passing a parameter to the HTTP Handler:
You can simply append a query string variable to the Response.Redirect(), like this:
Response.Redirect("PathToHttpHandler/DownloadFile.ashx?yourVariable=yourValue");
Then in the actual handler code you can use the Request object in the HttpContext to grab the query string variable value, like this:
System.Web.HttpRequest request = System.Web.HttpContext.Current.Request;
string yourVariableValue = request.QueryString["yourVariable"];
// Use the yourVariableValue here
Note - it is common to pass a filename as a query string parameter to suggest to the user what the file actually is, in which case they can override that name value with Save As...
Try this set of code to download a CSV file from the server.
byte[] Content= File.ReadAllBytes(FilePath); //missing ;
Response.ContentType = "text/csv";
Response.AddHeader("content-disposition", "attachment; filename=" + fileName + ".csv");
Response.BufferOutput = true;
Response.OutputStream.Write(Content, 0, Content.Length);
Response.End();
Simple solution for downloading a file from the server:
protected void btnDownload_Click(object sender, EventArgs e)
{
string FileName = "Durgesh.jpg"; // It's a file name displayed on downloaded file on client side.
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "image/jpeg";
response.AddHeader("Content-Disposition", "attachment; filename=" + FileName + ";");
response.TransmitFile(Server.MapPath("~/File/001.jpg"));
response.Flush();
response.End();
}
protected void DescargarArchivo(string strRuta, string strFile)
{
FileInfo ObjArchivo = new System.IO.FileInfo(strRuta);
Response.Clear();
Response.AddHeader("Content-Disposition", "attachment; filename=" + strFile);
Response.AddHeader("Content-Length", ObjArchivo.Length.ToString());
Response.ContentType = "application/pdf";
Response.WriteFile(ObjArchivo.FullName);
Response.End();
}
Further to Karl Anderson solution, you could put your parameters into session information and then clear them after response.TransmitFile(Server.MapPath( Session(currentSessionItemName)));.
See MSDN page HttpSessionState.Add Method (String, Object) for more information on sessions.
Making changes as below and redeploying on server content type as
Response.ContentType = "application/octet-stream";
This worked for me.
Response.Clear();
Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
Response.AddHeader("Content-Length", file.Length.ToString());
Response.ContentType = "application/octet-stream";
Response.WriteFile(file.FullName);
Response.End();
Source: Stackoverflow.com