RgnChange example for Visual C++ 5.0

RgnChange example for C++ 5.0 and later

This code for the RgnChange event updates a static text control using the GetRgnArea method. You can test it by adding a text box for the lesson described in Outlining, Dragging, and Pasting a Region.

The first two steps describe how to add a static text control. The last step shows the sample code.

1.	Add a Static Text control as follows:
	a.	In the Project Workspace, click the ResourceView tab.
	b.	Double-click the tutor resources folder to open it.
	c.	Double-click the Dialog folder to open it.
	d.	Double-click IDD_TUTOR_DIALOG to design the dialog box.
	e.	Click the Static Text control; then click and drag its shape in the dialog box.
	f.	Right-click the new control to edit its properties.
	g.	Change the ID to IDC_TEXT1.
	h.	Press Ctrl-F4 to close all windows back to the Project Workspace.
2.	Do the following to add m_Text1 to the CTutorDlg class and link the variable to the Static Text control using dynamic data exchange:
	a.	Press Ctrl-W to go to the MFC ClassWizard.
	b.	Click the Member Variables tab.
	c.	In the Class Name box, select CTutorDlg.
	d.	In the Control IDs list, select IDC_TEXT1.
	e.	Click the Add Variable... button.
	f.	Specify m_Text1 as the variable name, Control as the category, and Cstatic as the variable type.
	g.	Click OK to close the dialog box, and click OK to close the MFC ClassWizard.
3.	Use the MFC ClassWizard to add the RgnChange event, and code it as follows:

void CTutorDlg::OnRgnChangeLeadrasterview1()
{
   TCHAR szText[128];
   CRect rcWindow;
   m_LEADRasterView1.GetWindowRect(rcWindow);
   wsprintf(szText,
            TEXT("Number of pixels in region: %u "),
            m_LEADRasterView1.GetRaster().GetRgnArea());
   m_Text1.SetWindowText(szText);
   m_Text1.UpdateWindow();
}