How can I use “If” for download couldn't completed or download canceled VB.NET

Question

For example ,

My.Computer.Network.DownloadFile("https://dl.dropboxusercontent.com/u/71476794/Afterformatresources/vlc-2.1.2-win32.exe", "c:\Downloads\vlc.exe", "", "", True, 90, True, FileIO.UICancelOption.DoNothing)
    Process.Start("C:\Downloads\vlc.exe")

I want to deactive "process.start" command if download coudn't finish or canceled form user because of the NSIS error.

Answer 1

Use a Try Catch

Try
    My.Computer.Network.DownloadFile("https://dl.dropboxusercontent.com/u/71476794/Afterformatresources/vlc-2.1.2-win32.exe", "c:\Downloads\vlc.exe", "", "", True, 90, True, FileIO.UICancelOption.DoNothing)
    Process.Start("C:\Downloads\vlc.exe")

Catch ex as Exception
    'Exception caught. ex.message will contain some information
    'Handle error with messagebox or other means

Finally
    'Optional for code that will run whether Try was successful or not

End Try

Answer 2

There is a working example. I think it will be helpful if someone search this problem.

 Private Sub btnvlc_Click(sender As Object, e As EventArgs) Handles btnvlc.Click
    Try
        My.Computer.Network.DownloadFile("https://dl.dropboxusercontent.com/u/71476794/Afterformatresources/vlc-2.1.2-win32.exe", "c:\Downloads\vlc.exe", "", "", True, 90, True, FileIO.UICancelOption.ThrowException)
        Process.Start("C:\Downloads\vlc.exe")
    Catch ex As Exception
        MsgBox("Download expection occurred:" & vbCrLf & ex.Message)
    End Try
End Sub