Using the open file and save file dialogs in vb.net

Question

Once a user has selected a file with the open file dialog, how can I handle this action? For example, if the user has selected a .txt file and has opened it, how can it get the

Answer 1

You want to handle the FileOk event:

Private Sub OpenFileDialog1_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles OpenFileDialog1.FileOk
    Dim path As String = OpenFileDialog1.FileName

    If fileIsBitmap Then
        ' say the file is a bitmap image '
        Dim bmp As New Bitmap(path)

        ' rotate the image 90 degrees '
        bmp.RotateFlip(RotateFlipType.Rotate90FlipNone)

        ' save the image '
        bmp.Save(path)

    ElseIf fileIsTextFile Then
        ' or say the file is a text file '
        Dim fs As New IO.FileStream(path, IO.FileMode.Append)
        Dim sr As New IO.StreamWriter(fs)

        ' write a new line at the end of the file '
        sr.WriteLine("This is a new line.")

        ' close the FileStream (this saves the file) '
        sr.Close()
        fs.Close()
    End If
End Sub

Answer 2

Here is some good example: https://web.archive.org/web/1/http://blogs.techrepublic%2ecom%2ecom/programming-and-development/?p=481.

This is a trivial question that could be answered by Google in a matter of seconds.

Answer 3

Dim dlg_open As New OpenFileDialog()
If (dlg_open.Show() <> DialogResult.OK) Then Return

'if a textfile, then
Dim content As String() = IO.File.ReadAllLines(dlg_open.FileName)

'if an image, then
Dim img As New Bitmap(dlg_open.FileName)

You should put Try...Catch blocks around all operations dealing with IO, you will not be able to prevent all exceptions.