Visual Basic.NET How to Program (PDF)

578 Graphical User Interfaces Concepts: Part 2 Chapter 13
Fig. 13.39 Class FrmInheritance, which inherits from class Form, contains a
button (Learn More) (part 2 of 2).
Fig. 13.40 Visual Inheritance through the Form Designer.
Class FrmVisualTest (Fig. 13.41) is a derived class of class Visual-
Form.FrmInheritance. The output illustrates the functionality of the program. The
GUI contains those components derived from class FrmInheritance, as well as an
additional button with text Learn The Program. When a user presses this button, method
cmdProgram_Click (lines 13–20) is invoked. This method displays another message
box providing different informative text.
Figure 13.41 demonstrates that the components, their layouts and the functionality of
base-class FrmInheritance (Fig. 13.39) are inherited by FrmVisualTest. If a user
clicks button Learn More, the base-class event handler cmdLearn_Click displays a
MessageBox. FrmInheritance uses a Friend access modifier to declare its controls,
so class FrmVisualTest cannot modify the controls inherited from class FrmIn-