Download button - Xtreme Visual Basic Talk

04-14-2012, 06:52 AM

Alex30

Regular

Join Date: Sep 2007

Posts: 50

Download button

Hi,
In my project, I've created a download button.

This button shall perform 3tasks:
1. Change label text
2. Download file
3. Make the button invisible

The following code changes the label text and make the button invisible:

Code:

Protected Sub btnDownload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDownload.Click
              
        lblDownload.Text = "<h3>Thank you for downloading </h3>" 
        btnDownload.Visible = False

    End Sub

When I add a piece of code that handles the file download, the label text is not changed and button remains visible.
Here is the code:

Code:

Protected Sub btnDownload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDownload.Click
        Dim URL As String = "~/myfile.exe"
        Dim fileInfo As FileInfo = New FileInfo(Server.MapPath(URL))


        If fileInfo.Exists Then
            Response.Clear()
            Response.AddHeader("Content-Disposition", "attachment; filename=" + fileInfo.Name)
            Response.AddHeader("Content-Length", fileInfo.Length.ToString())
            Response.ContentType = "application/octet-stream"
            Response.Flush()
            Response.WriteFile(fileInfo.FullName)
        End If

        lblDownload.Text = "<h3>Thank you for downloading</h3>"
        btnDownload.Visible = False

    End Sub

File downloading cancels other operations.

Do you have any ideas?

04-16-2012, 09:38 AM

DrPunk

Senior Contributor

* Expert *

Join Date: Apr 2003

Location: Never where I want to be

Posts: 1,272

Change the text and hide the button before doing the file download...

Code:

Protected Sub btnDownload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDownload.Click
        Dim URL As String = "~/myfile.exe"
        Dim fileInfo As FileInfo = New FileInfo(Server.MapPath(URL))

        If fileInfo.Exists Then

            lblDownload.Text = "<h3>Thank you for downloading</h3>"
            btnDownload.Visible = False

            Response.Clear()
            Response.AddHeader("Content-Disposition", "attachment; filename=" + fileInfo.Name)
            Response.AddHeader("Content-Length", fileInfo.Length.ToString())
            Response.ContentType = "application/octet-stream"
            Response.Flush()
            Response.WriteFile(fileInfo.FullName)
        End If

    End Sub

Your code waits on Response.Writefile until it has finished, so therefore wasn't doing the other lines until it had finished.

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