Obtains the display ID number for a video device.

OSErr DMGetDisplayIDByGDevice (
    GDHandle displayDevice, 
    DisplayIDType *displayID, 
    Boolean failToMain
);

Parameter descriptions

displayDevice

A handle to the GDevice structure for the video device whose display ID you wish to obtain.

displayID

On return, a pointer to the display ID for the video device specified by the displayDevice parameter.

failToMain

If true and the specified video device does not have a display ID, on return the function sets the displayID parameter to a pointer to the display ID of the video device for the main screen. If false and the specified video device does not have a display ID, the function returns the kDMDisplayNotFoundErr result code.

function result

A result code.

SPECIAL CONSIDERATIONS

Because this function may move or purge memory blocks or access handles, you cannot call it at interrupt time.

AVAILABILITY

Supported in Carbon. Available in Carbon 1.0.2 and later when running Mac OS 8.1 or later.

© 2000 Apple Computer, Inc. (Last Updated 6/30/2000)