Section A.1. Disk IO: Reading

A.1. Disk I/O: Reading

The "Open a File" button displays an Open File dialog window to allow users to select a file. Once you've selected a file, you will read its content and display it in a message box:

 '===================================================     ' Open a File     '===================================================     Private Sub btnOpenFile_Click( _        ByVal sender As System.Object, _        ByVal e As System.EventArgs) _        Handles btnOpenFile.Click         '---Create an OpenFileDialog to request a file to open---         Dim openFile1 As New OpenFileDialog()         '---Initialize the OpenFileDialog to look for txt files---         openFile1.DefaultExt = "*.txt"     openFile1.Filter = "Text Files|*.txt"     '---Determine whether the user selected a file from the     ' OpenFileDialog---     If (openFile1.ShowDialog() = _         System.Windows.Forms.DialogResult.OK) _         And (openFile1.FileName.Length > 0) Then         '---Read the content of file---         MsgBox("Content of file: "&_            My.Computer.FileSystem.ReadAllText(openFile1.FileName))     End If End Sub