The IsDialogMessage function determines whether a message is intended for the specified dialog box and, if it is, processes the message.
BOOL IsDialogMessage(
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HWND hDlg, |
// handle of dialog box |
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LPMSG lpMsg |
// address of structure with message |
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); |
If the message has been processed, the return value is nonzero.
If the message has not been processed, the return value is zero.
Although the IsDialogMessage function is intended for modeless dialog boxes, you can use it with any window that contains controls, enabling the windows to provide the same keyboard selection as is used in a dialog box.
When IsDialogMessage processes a message, it checks for keyboard messages and converts them into selection commands for the corresponding dialog box. For example, the TAB key, when pressed, selects the next control or group of controls, and the DOWN ARROW key, when pressed, selects the next control in a group.
Because the IsDialogMessage function performs all necessary translating and dispatching of messages, a message processed by IsDialogMessage must not be passed to the TranslateMessage or DispatchMessage function.
IsDialogMessage sends WM_GETDLGCODE messages to the dialog box procedure to determine which keys should be processed.
IsDialogMessage can send DM_GETDEFID and DM_SETDEFID messages to the window. These messages are defined in the WINUSER.H header file as WM_USER and WM_USER + 1, so conflicts are possible with application-defined messages having the same values.
DispatchMessage, DM_GETDEFID, DM_SETDEFID, MSG, TranslateMessage, WM_GETDLGCODE, WM_USER