click event handler
of it and do the following code for getting all .txt file in a certain directory when the button is clicked.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click Dim folderBrowseDialog As FolderBrowserDialog = New FolderBrowserDialog() folderBrowseDialog.SelectedPath = "C:\" Dim driNFO As New DirectoryInfo(folderBrowseDialog.SelectedPath) Dim txtFiles As FileInfo() = driNFO.GetFiles("*.txt") ListBox1.Items.Clear() For Each txt_file As FileInfo In txtFiles ListBox1.Items.Add(txt_file.Name) Next End Sub