共用方式為

IWMDMStorageControl::Read

  • 發行項
banner art

The Read method copies the current storage to the computer.

Syntax

HRESULT Read(UINTfuMode,
LPWSTR  pwszFilename,IWMDMProgress*pProgress,IWMDMOperation*pOperation);

Parameters

fuMode

[in]  Processing mode used for the Read operation. The following table lists the processing modes that can be specified in the fuMode parameter. You must specify exactly one of the first two modes, and exactly one of the last three (WMDM_CONTENT) modes. If both WMDM_MODE_BLOCK and WMDM_MODE_THREAD are specified, block mode is used.

Mode Description
WMDM_MODE_BLOCK The operation is performed using block mode processing. The call will not return until the operation is finished.
WMDM_MODE_THREAD The operation is performed using thread mode processing. The call will return immediately, and the operation is performed in a background thread.
WMDM_CONTENT_FILE The caller requests that Windows Media Device Manager read the file from the portable device into a file on the hard disk. The caller should indicate, in the pwszFileName parameter, the full path and name of the file.
WMDM_CONTENT_FOLDER The caller requests that Windows Media Device Manager read the specified folder, the contents, of the folder and the contents of any subfolders from the portable device onto the hard disk. The caller should indicate the full path of the target directory on the hard disk in the pwszFileName parameter.

This is not currently supported by any Microsoft-provided service providers.
WMDM_CONTENT_OPERATIONINTERFACE The application-implemented IWMDMOperation interface is being used to read data, instead of passing in a file name.

pwszFilename

[in]  Pointer to a fully-qualified file name on the computer to which the content from the portable device is copied. The file name should include an extension; the extension from the current storage on the device will not be used. If WMDM_CONTENT_OPERATIONINTERFACE is specified in fuMode, this parameter is ignored.

pProgress

[in]  Optional pointer to a IWMDMProgress interface that has been implemented by the application to track the progress of ongoing operations.

pOperation

[in]  Optional pointer to an IWMDMOperation interface, an optional set of methods used to enhance the transfer of content from a media device. This parameter must be NULL if WMDM_CONTENT_FILE or WMDM_CONTENT_FOLDER is specified in fuMode.

Return Values

The method returns an HRESULT. All the interface methods in Windows Media Device Manager 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 an extenstive 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_INTERFACEDEAD The file or folder was previously deleted.
E_BUSY The media device is already busy with another operation.
E_INVALIDARG One or more parameters are invalid or NULL.
E_NOTCERTIFIED Permission to read has been denied.
E_FAIL An unspecified error occurred.
WMDM_E_NOTCERTIFIED The caller is not certified
WMDM_E_MAC_CHECK_FAILED The message authentication check failed.

Remarks

This method will automatically overwrite existing files specified by pwszFilename. It can succeed even if

If the WMDM_MODE_THREAD flag is specified, you should obtain completion status by calling either IWMDMProgress2::End2 or IWMDMProgress3::End3. These methods will ensure that the operation is complete and will also return an HRESULT with success or failure information.

If an application uses WMDM_MODE_THREAD and passes a non-null pProgress parameter, the application must ensure that the object to which pProgress belongs is not destroyed until the read operation completes, because Windows Media Device Manager will send progress notifications to this object. This object can be destroyed only after it receives an End notification. Failure to do this will result in access violations.

Requirements

Header: Defined in mswmdm.h.

Library: mssachlp.lib

See Also