Subclassing and Hooking with Visual Basic

A Thread-Specific Example

This first example illustrates the information that you can obtain from the WH_CBT hook. Figure 18-1 shows a screenshot of the application. This application contains a menu bar with the Test menu item, a CreateWnd button, and a MSGBOX button. Each item will aid in our understanding of this hook.

Figure 18-1. Screenshot of the WH_CBT application

Table 18-6 presents the nondefault properties of the form and its controls.

Table 18-6. Nondefault Properties of the Form and Its Controls

Object	Property Name	Property Value
Form1	Name	Form2
Form1	Caption	“WH_CBT Application”
Form1	Top	330
Form1	Left	105
Form1	Height	4710
Form1	Width	7095
Form2	Name	Form1
Form2	Caption	“NEW FORM”
Command Button1	Name	cmdHook
Command Button1	Caption	“hook”
Command Button1	Top	120
Command Button1	Left	120
Command Button1	Height	300
Command Button1	Width	915
Command Button2	Name	cmdUnhook
Command Button2	Caption	“unhook”
Command Button2	Top	780
Command Button2	Left	120
Command Button2	Height	300
Command Button2	Width	915
Command Button3	Name	cmdCreateWnd
Command Button3	Caption	“CreateWnd”
Command Button3	Top	3180
Command Button3	Left	120
Command Button3	Height	315
Command Button3	Width	1395
Command Button4	Name	cmdMsgBox
Command Button4	Caption	“MsgBox”
Command Button4	Top	3900
Command Button4 ...