joySetCapture function (joystickapi.h)

Article
02/22/2024

The joySetCapture function captures a joystick by causing its messages to be sent to the specified window.

Syntax

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.

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 value

Returns JOYERR_NOERROR if successful or one of the following error values.

Return code	Description
MMSYSERR_NODRIVER	The joystick driver is not present.
MMSYSERR_INVALPARAM	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	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

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	joystickapi.h (include Windows.h)
Library	Winmm.lib
DLL	Winmm.dll