IWMDMOperation::BeginRead
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The BeginRead method indicates that a read operation is being started by a method belonging to the IWMDMStorageControl interface.
Syntax
HRESULT BeginRead();
Parameters
This method takes no parameters.
Return Values
The method returns an HRESULT. All the interface methods in Windows Media Device Manager and service provider can return any of the following classes of error codes:
- Standard COM error codes
- Windows error codes converted to HRESULT values
- Windows Media Device Manager error codes
For a complete list of possible error codes, see Error Codes.
Possible values include, but are not limited to, those in the following table.
| Return code | Description |
| S_OK | The method succeeded. |
| WMDM_E_USER_CANCELLED | The application instructs Windows Media Device Manager to cancel the current operation without waiting for it to finish. |
| E_FAIL | An unspecified error occurred. |
Remarks
When the method to which this interface has been passed is beginning to read data, the BeginRead method must be the first in the IWMDMOperation interface to be called. If either E_FAIL or WMDM_E_USER_CANCELLED is returned, the End method is called to indicate that the process has been terminated. If the application is using block mode and returns WMDM_E_USER_CANCELLED, then Windows Media Device Manager will return this same error to the application.
Requirements
Header: Defined in wmdm.idl.
Library: mssachlp.lib
See Also