Subclassing and Hooking with Visual Basic

A Thread-Specific Example

The example presented here is a thread-specific example that installs the WH_SHELL hook and displays shell notification messages as they occur. Figure 17-3 provides a screenshot of the example application.

Figure 17-3. Screenshot of example application

Table 17-4 presents the nondefault properties of the form and its controls.

Using the Application

The application works like the previous examples. Click the hook button to install the hook and the unhook button to remove the hook. The hook and unhook buttons in the SHELL frame deal with the WH_SHELL hook. The following three extra buttons are included as well:

Create Wnd

Creates and displays a form using the code Load Form1.

TaskBar Title

Changes the text in the window title bar from “WH_SHELL Example” to “Title of Window Has Changed”. Note that changing the top-level unowned window’s title text causes the same text to be displayed in the task bar for this window.

MsgBox

Displays a simple message box.

Table 17-4. Nondefault Properties of the Form and Its Controls

Object	Property Name	Property Value
Form1	Name	Form2
Form1	Caption	“WH_SHELL Example”
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 ...