Sample Code Demonstrates Using Private Dialog-Box Class

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.1 and 3.0

SUMMARY

PVTDLG is a file in the Microsoft Software Library that demonstrates using a private dialog-box class in an application. The PVTDLG application demonstrates using a private dialog-box class by itself and in conjunction with another dialog box procedure. PVTDLG registers a private dialog-box class that specifies a number of additional window extra bytes. The sample stores the colors to paint each window in the allocated space.

Download PVTDLG.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:

• Microsoft Download Service (MSDL)

        Dial (206) 936-6735 to connect to MSDL
        Download PVTDLG.EXE (size: 30839 bytes) 
  

• Internet (anonymous FTP)

        ftp ftp.microsoft.com
        Change to the \SOFTLIB\MSLFILES directory
        Get PVTDLG.EXE (size: 30839 bytes) 
  

MORE INFORMATION

A private dialog-box class is a technique that allows one callback procedure to process messages that are common to several different dialog boxes. The private dialog-box class encapsulates code that would otherwise be repeated in each dialog procedure.

When Windows has a message for a dialog box that is a member of a private dialog-box class, it calls the private dialog-box class procedure. After the private dialog-box class procedure completes its processing, it must call the DefDlgProc function.

The next step depends on the contents of the lpDialogFunc parameter in the application's call to the CreateDialog or DialogBox functions. If lpDialogFunc is NULL, the DefDlgProc function performs its default processing for the message and processing of that message is complete. If lpDialogFunc is not NULL, DefDlgProc calls the specified procedure. If the dialog box procedure returns FALSE, DefDlgProc performs its default processing for the message. If the dialog box procedure returns any other value, DefDlgProc skips the default processing and returns.