The first example in the chapter is a very simplified Help window. Although the purpose of this example is really just to demonstrate how to manage multiple forms in a project, you might be left with the impression that this is the recommended way to provide help screens for your system.

NOTHING could be further from the truth!

One of the bigger upgrades in VB.NET is the addition of new ways to provide help in a system. Most of them are based on extensions to VB.NET forms. Studying the ways help can be provided in VB.NET illustrateS both how an important VB.Net Namespace - Forms - is extended, and also shows you some valuable programming tips for help that you can use in your code.

Help can be very sophisticated and complex or very simple. Here's an overview.

1. Load the "Multiple Forms" project from the library of projects provided with the book from the folder for Chapter 15.
2. Delete the Help Button from the Lucky Seven form and the event subroutine that handles it (Button3_Click).
3. Open the Properties window for the Lucky Seven form (named Form1) and change ...
   
   HelpButton     True
   MaximizeBox    False
   MinimizeBox     False
   
   The HelpButton property has no effect unless the MaximizeBox and the MinimizeBox are disabled.

Now it's time to add the programming that will display the same ReadMe.txt file using the HelpButton object. This object will raise an event called HelpRequested for specific components, or using the HelpButton. To do this ...

4. Add the following code to the Form1 class. Since this is just a modification of the code that is provided in the book, it's easier (and more error proof) to copy and paste it, then change the parts of the code that are different.

Private Sub textBox_HelpRequested( _
    ByVal sender As Object, _
    ByVal hlpevent _
      As System.Windows.Forms.HelpEventArgs) _
    Handles MyBase.HelpRequested
    ' This event is raised 
    ' when the F1 key is pressed or the
    ' Help cursor is clicked 
    ' on any of the component fields.
    Dim StreamToDisplay As StreamReader
    Dim frmDialog As New HelpInfo
    frmDialog.ShowDialog()
    StreamToDisplay = _
      New StreamReader( _
      "c:\vbnet03sbs\chap14\readme.txt")
    frmDialog.Text = StreamToDisplay.ReadToEnd
    StreamToDisplay.Close()
    hlpevent.Handled = True
End Sub 'textBox_HelpRequested

5. Finally, remember to add this statement at the top of the program ...


Imports System.IO 'for StreamReader class

To use the HelpButton, click the button (it's the one with the question mark in it at the top right) then click inside any of the components. If you click on a blank spot in the form, nothing will happen. This is because the HelpButton is designed to allow you to display different things for different components but in this simplified example, we just selected all of the components - but not the form - using the Handles MyBase.HelpRequested clause in the Sub textBox_HelpRequested declaration. The cursor then changes into the HelpRequsted cursor and when you click again, the Sub textBox_HelpRequested code is executed to display the file. The HelpRequested event code is also executed if you press F1.