joySetCapture
The joySetCature function captures a joystick by causing its messages to be sent to the specified window.
MMRESULT joySetCapture(
HWND hwnd,
UINT uJoyID,
UINT uPeriod,
BOOL fChanged
);
Parameters
hwnd
Handle to the window to receive the joystick messages.
uJoyID
Identifier of the joystick to be captured. Valid values for uJoyID range from zero (JOYSTICKID1) to 15, except for Windows NT 4.0. For Windows NT 4.0, valid values are limited to JOYSTICKID1 and JOYSTICKID2.
uPeriod
Polling frequency, in milliseconds.
fChanged
Change position flag. Specify TRUE for this parameter to send messages only when the position changes by a value greater than the joystick movement threshold. Otherwise, messages are sent at the polling frequency specified in uPeriod.
Return Values
Returns JOYERR_NOERROR if successful or one of the following error values.
| Value | Description |
| MMSYSERR_NODRIVER | The joystick driver is not present. |
| MMSYSERR_INVALPARAM | Windows 95/98/Me: Invalid joystick ID or hwnd is NULL. |
| JOYERR_NOCANDO | Cannot capture joystick input because a required service (such as a Windows timer) is unavailable. |
| JOYERR_UNPLUGGED | The specified joystick is not connected to the system. |
| JOYERR_PARMS | Windows NT/2000/XP: Invalid joystick ID or hwnd is NULL. |
Remarks
If the specified joystick is currently captured, the function returns undefined behavior. Call the joyReleaseCapture function to release the captured joystick, or destroy the window to release the joystick automatically.
Requirements
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
** Header:** Declared in Mmsystem.h; include Windows.h.
** Library:** Use Winmm.lib.
See Also