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IPortableDeviceContent::CreateObjectWithPropertiesAndData

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IPortableDeviceContent::CreateObjectWithPropertiesAndData

The CreateObjectWithPropertiesAndData method creates an object with both properties and data on the device.

Syntax

  HRESULT CreateObjectWithPropertiesAndData(
  IPortableDeviceValues*  pValues,
  IStream**  ppData,
  DWORD*  pdwOptimalWriteBufferSize,
  LPWSTR*  ppszCookie
);

Parameters

pValues

An IPortableDeviceValues collection of properties to assign to the object. For a list of required and optional properties for an object, see Requirements for Objects.

ppData

[out]  Address of a variable that receives a pointer to an IStream interface that the application uses to send the object data to the device. The object will not be created on the device until the application sends the data by calling ppData->Commit. To abandon a data transfer in progress, you can call ppData->Revert. The caller must release this interface when it is done with it. The underlying object extends both IStream and IPortableDeviceDataStream.

pdwOptimalWriteBufferSize

[in, out]  An optional DWORD pointer that specifies the optimal buffer size for the application to use when writing the data to ppData. The application can specify NULL to ignore this.

ppszCookie

[in, out]  An optional unique, null-terminated string ID that is used to identify this creation request in the application's implementation of IPortableDeviceEventCallback (if implemented). When the device finishes creating the object, it will send this identifier to the callback function. This identifier allows an application to monitor object creation in a different thread from the one that called CreateObjectWithPropertiesAndData. The SDK allocates this memory, and the caller must release it using CoTaskMemFree.

Return Values

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.
E_POINTER At least one of the required arguments was a NULL pointer.

Remarks

Some objects are only a collection of properties—such as a folder, which is only a collection of pointers to other objects—while other objects are both properties and data—such as an audio file, which contains all the properties and the actual music bits. This method is used to create an object that requires both properties and data. To create a properties-only object, call CreateObjectWithPropertiesOnly.

Because the object is not created until the application calls Commit on the retrieved IStream ppData, the object will not have an ID until Commit is called on it. Commit is synchronous, so when that method returns successfully, the object will exist on the device.

After calling Commit to create the object, call QueryInterface on ppData for IPortableDeviceDataStream, and then call IPortableDeviceDataStream::GetObjectID to get the ID of the newly created object.

Requirements

Header: Defined in PortableDeviceApi.h

Library: PortableDeviceGUIDs.lib

See Also

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