Folder Browser Replacement - vb.net

Question

I want to be able to add multiple download links and for them to go into a single folder which is selected by the user in a Folder Browser Dialog
The code you see below works great except only for a single file. I have tried changing all 'savefiledialog1' to 'folderbrowserdialog1' instead. However this leads to me clicking download and nothing happening even if only a single link is entered.
Private Sub BtnBrowse_Click(sender As Object, e As EventArgs) Handles btnBrowse.Click
If (SaveFileDialog1.ShowDialog() = DialogResult.OK) Then
txtSave1.Text = SaveFileDialog1.FileName
btnDownload.Enabled = True
End If
End Sub
' ------------ DOWNLOADING SECTION ------------
Private WithEvents HTTPCLIENT As WebClient
Private Sub BtnDownload_Click(sender As Object, e As EventArgs) Handles
btnDownload.Click
btnDownload.Enabled = False
txtSave1.Enabled = False
btnBrowse.Enabled = False
btnDownload.Enabled = False
HTTPCLIENT = New WebClient
Dim Download As String
Download = Links(i)
Dim User = Environment.UserName
Dim Save As String = txtSave1.Text
Try
HTTPCLIENT.DownloadFileAsync(New Uri(Download), Save)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
I expected the folder browser dialog to just be a general save path where the file being downloaded is placed into that folder, however I am given an error.
The code above works but only for a single file.
I have code that can retrieve the download name and extension which I plan to add to the path once i figure this part out.

Answer 1

You can use the FolderBrowserDialog. Once you get the path, you combine it with each filename you will download. Use System.IO.Path.Combine()
Private Sub BtnBrowse_Click(sender As Object, e As EventArgs) Handles btnBrowse.Click
Using fbd As New FolderBrowserDialog()
If fbd.ShowDialog() = DialogResult.OK Then
txtSave1.Text = fbd.SelectedPath
btnDownload.Enabled = True
End If
End Using
End Sub
Private Sub BtnDownload_Click(sender As Object, e As EventArgs) Handles btnDownload.Click
Try
btnDownload.Enabled = False
txtSave1.Enabled = False
btnBrowse.Enabled = False
btnDownload.Enabled = False
Dim exceptionMessages As New List(Of String)
Using client = New WebClient()
' configure client here as needed i.e. add Credentials
For Each link In Links
Try
client.DownloadFileAsync(New Uri(link), Path.Combine(txtSave1.Text, link))
Catch ex As Exception
exceptionMessages.Add(ex.Message)
End Try
Next
End Using
If exceptionMessages.Any() Then MessageBox.Show($"Exception{If(exceptionMessages.Count > 1, "s", "")}: {String.Join(Environment.NewLine, exceptionMessages)}")
Finally
txtSave1.Enabled = True
btnBrowse.Enabled = True
btnDownload.Enabled = True
End Try
End Sub
Note that I will not post an answer with IDisposable objects without Using (in most cases) so FolderBrowserDialog and WebClient are both in Usings. You may need to add additional configuration to the WebClient before downloading.
Also, you probably don't want a separate message for each Exception, if any. So the messages can be cached and shown all at once.
I inserted a Finally for you to set control states back to default when done. This is up to you.
Lastly, the work is being done on a UI thread as evidenced by it being one inside the button click handler. You should move it off the UI even though you aren't blocking. This is outside the scope of the question.