The WM_INPUTLANGCHANGEREQUEST message is posted to the window with the focus when the user chooses a new input language, either with the hotkey (specified in the Keyboard control panel application) or from the indicator on the system taskbar. An application can accept the change by passing the message to the DefWindowProc function or reject the change (and prevent it from taking place) by returning immediately.
A window receives this message through its WindowProc function.
Syntax
WM_INPUTLANGCHANGEREQUEST
WPARAM wParam
LPARAM lParam;
Parameters
- wParam
-
Information about the new input locale. This parameter can be a combination of the following flags.
INPUTLANGCHANGE_BACKWARD- Windows 2000/XP: A hot key was used to choose the previous input locale in the installed list of input locales. This flag cannot be used with the INPUTLANGCHANGE_FORWARD flag.
INPUTLANGCHANGE_FORWARD- Windows 2000/XP: A hot key was used to choose the next input locale in the installed list of input locales. This flag cannot be used with the INPUTLANGCHANGE_BACKWARD flag.
INPUTLANGCHANGE_SYSCHARSET- Windows 2000/XP: The new input locale's keyboard layout can be used with the system character set.
- lParam
-
Input locale identifier. For more information, see Languages, Locales, and Keyboard Layouts.
Return Value
This message is posted, not sent, to the application, so the return value is ignored. To accept the change, the application should pass the message to DefWindowProc. To reject the change, the application should return zero without calling DefWindowProc.
Remarks
When the DefWindowProc function receives the WM_INPUTLANGCHANGEREQUEST message, it activates the new input locale and notifies the application of the change by sending the WM_INPUTLANGCHANGE message.
The language indicator is present on the taskbar only if you have installed more than one keyboard layout and if you have enabled the indicator using the Keyboard control panel application.
Notification Requirements
| Minimum DLL Version |
None |
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| Header | Declared in Winuser.h, include Windows.h |
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| Minimum operating systems |
Windows 95, Windows NT 4.0 |
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See Also