IDirectSound8::SetCooperativeLevel Method

發行項
09/10/2011

[The feature associated with this page, DirectSound, is a legacy feature. It has been superseded by WASAPI and Audio Graphs. Media Casting have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Media Casting instead of DirectSound, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The SetCooperativeLevel method sets the cooperative level of the application for this sound device.

Syntax

HRESULT SetCooperativeLevel(
         HWND hwnd,
         DWORD dwLevel
)

Parameters

hwnd
Handle to the application window.

dwLevel
Requested level. Specify one of the values shown in the following table.

Value	Description
DSSCL_EXCLUSIVE	For DirectX 8.0 and later, has the same effect as DSSCL_PRIORITY. For previous versions, sets the application to the exclusive level. This means that when it has the input focus, the application will be the only one audible; sounds from applications with the DSBCAPS_GLOBALFOCUS flag set will be muted. With this level, it also has all the privileges of the DSSCL_PRIORITY level. DirectSound will restore the hardware format, as specified by the most recent call to the SetFormat method, after the application gains the input focus.
DSSCL_NORMAL	Sets the normal level. This level has the smoothest multitasking and resource-sharing behavior, but because it does not allow the primary buffer format to change, output is restricted to the default 8-bit format.
DSSCL_PRIORITY	Sets the priority level. Applications with this cooperative level can call the SetFormat and Compact methods.
DSSCL_WRITEPRIMARY	Sets the write-primary level. The application has write access to the primary buffer. No secondary buffers can be played. This level cannot be set if the DirectSound driver is being emulated for the device; that is, if the GetCaps method returns the DSCAPS_EMULDRIVER flag in the DSCAPS structure.

Return Value

If the method succeeds, the return value is DS_OK. If the method fails, the return value may be one of the error values shown in the following table.

Return code

Remarks

The application must set the cooperative level by calling this method before its buffers can be played. The recommended cooperative level is DSSCL_PRIORITY.

Do not call this method if any buffers are locked.

Requirements

Header: Declared in DSound.h.

Library: Use Dsound3d.dll.

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