You want to display a picture with full resolution, but you want to let the user scroll around to see all parts of the picture.
Sample code folder: Chapter 10\ScrollImage
Store the picture in a PictureBox with its SizeMode property set to AutoSize, and place it on a form with its AutoScroll property set to true.
To see this demonstration in action, add a PictureBox to a form, set its SizeMode property to AutoSize, and set its Location property to 0,0. Don't worry about its size; the AutoSize setting will take care of that. Change the form's AutoScroll property to true. Now add the following code to the form's class, which loads a picture on startup:
Private Sub Form1_Load(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles Me.Load ' ----- Let the user choose a picture. Dim locateFile As New OpenFileDialog ' ----- Prompt for the initial file. locateFile.Filter = "JPG files (*.jpg)|*.jpg" locateFile.Multiselect = False If (locateFile.ShowDialog( ) = _ Windows.Forms.DialogResult.OK) Then ' ----- Show the selected picture. PictureBox1.Load(locateFile.FileName) Me.AutoScroll = True Else ' ----- Exit the program. Me.Close( ) End If End Sub
Run the program, and select a large picture. The scrollbars will automatically appear when needed, as shown in Figure 10-19.
Figure 10-19. Implementing scrollbars to enable scrolling around large images