Show Download Image Popup On Button Click...

How to show the download Popup when we click on the button?

Add this code in Button Click Event

 Protected Sub btnExportToImage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnExportToImage.Click
{
 Response.ContentType = "png"
 Response.AppendHeader("Content-Disposition", "attachment; filename=TopIndustry.png")
 Response.TransmitFile(Server.MapPath("~/TempImageFiles/" + Session("ImageName").ToString()))
 Response.End()
}

- Image is stored on the server.

- so in this example image name is set on runtime and stored in to the session.

- On button click 

End Sub


It will show the Output: