IWMPSubscriptionService2::deviceAvailable method (subscriptionservices.h)

Artikel
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 It has been superseded by MediaPlayer.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 deviceAvailable method is implemented by the online store to initiate device-specific processing tasks.

Syntax

HRESULT deviceAvailable(
  [in] BSTR                            bstrDeviceName,
  [in] IWMPSubscriptionServiceCallback *pCB
);

Parameters

[in] bstrDeviceName

String containing the device name.

[in] pCB

Pointer to an IWMPSubscriptionServiceCallback interface. The online store uses this pointer to notify Windows Media Player that device-specific processing is complete.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code	Description
S_OK	The method succeeded.

Remarks

Windows Media Player calls this method after a synchronization operation if the time elapsed since the last call is one week or more.

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. When the worker thread has completed its work, it must call IWMPSubscriptionServiceCallback::onComplete.

Use the following procedure to provide your worker thread with a pointer to an IWMPSubscriptionServiceCallback interface.

Pass pCB to CoMarshalInterThreadInterfaceInStream, which returns an IStream pointer.
Pass the IStream pointer to your worker thread.
In your worker thread, call CoGetInterfaceAndReleaseStream, which returns an interface pointer that you can use to call onComplete.

The string contained in bstrDeviceName is not the same name retrieved by using IWMPSyncDevice::get_deviceName. Rather, it is the canonical name retrieved by using the IWMDMDevice2::GetCanonicalName method provided by the Windows Media Device Manager SDK.

Requirements

Requirement	Value
Minimum supported client	Windows Media Player 10 or later.
Target Platform	Windows
Header	subscriptionservices.h

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