Ensure Appearance of Open/Save Dialog On File Download from Web Page (ASP.NET)

Category:

C#, VB.NET, ASP.NET

Type:

Snippets

Difficulty:

Intermediate

Author:

Intelligent Solutions Inc.

Version Compatibility: ASP.NET

More information:

Many file types, such as MS Word files, .pdf files automatically open in the client's browser when they are downloaded. To override this behavior and display the save/open dialog, you can use this ASP.NET code. Demo usage is included.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

'Put this is a code behind module or asp.net page
Sub DisplayDownloadDialog(ByVal PathVirtual As String)

Dim strPhysicalPath As String
        Dim objFileInfo As System.IO.FileInfo
        Try
            strPhysicalPath = Server.MapPath(PathVirtual)
            'exit if file does not exist
            If Not System.IO.File.Exists(strPhysicalPath) _
                 Then Exit Sub
            objFileInfo = New System.IO.FileInfo(strPhysicalPath)
            Response.Clear()
           'Add Headers to enable dialog display
            Response.AddHeader("Content-Disposition", "attachment; filename=" & _
                objFileInfo.Name)
            Response.AddHeader("Content-Length", objFileInfo.Length.ToString())

Response.ContentType = "application/octet-stream"
            Response.WriteFile(objFileInfo.FullName)

Catch
            'on exception take no action
            'you can implement differently
        Finally

Response.End()

End Try
    End Sub
'DEMO
'IN YOUR CODE BEHIND PAGE:
'DECLARATION
Protected WithEvents btnDownload As _
  System.Web.UI.WebControls.Button

'IN CODE
'ASSUMES MYWORDFILE.DOC EXISTS IN SAME FOLDER
'AS THE ASPX FILE
 Private Sub btnDownload_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) _
          Handles btnDownload.Click
        DisplayDownloadDialog("MyWordFile.doc")
 End Sub
'ON APSX PAGE
<asp:Button id="btnDownload" runat="server" Text="Download a Word File"></asp:button>