IWMPSubscriptionService::allowPlay method (subscriptionservices.h)

아티클
4/26/2023

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 It has been superseded by MediaPlayer.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

Note This section describes functionality designed for use by online stores. Use of this functionality outside the context of an online store is not supported.

The allowPlay method is implemented by the online store's plug-in to manage permission for Windows Media Player to play content.

Syntax

HRESULT allowPlay(
  [in]  HWND      hwnd,
  [in]  IWMPMedia *pMedia,
  [out] BOOL      *pfAllowPlay
);

Parameters

[in] hwnd

A handle to a window in which the plug-in can display a user interface.

[in] pMedia

Pointer to the media object Windows Media Player is attempting to play.

[out] pfAllowPlay

Pointer to a BOOL. If true, playback is allowed.

Return value

The method returns an HRESULT.

Remarks

Your code should not perform lengthy operations synchronously when Windows Media Player calls this method. Instead, you must perform time-consuming tasks on a separate worker thread.

Windows Media Player calls allowPlay before opening the digital media file. This gives the online store an opportunity to disallow playback of licensed content or to initiate download of a new license if the license has expired.

Because the digital media file is not open when Windows Media Player calls allowPlay, calling certain methods on pMedia may not work. For instance, attempting to retrieve metadata using IWMPMedia::getItemInfo could fail.

The allowPlay method does not circumvent DRM. If the method returns TRUE and the license to play has not been renewed, Windows Media Player will not play the content.

The allowPlay method is not called when streaming protected content for which the user does not have a license.

Requirements


Minimum supported client	Windows Media Player 9 Series or later.
Target Platform	Windows
Header	subscriptionservices.h