罗列手机上所有的磁盘标识符。

    RFs fileServerSession;
    User::LeaveIfError(fileServerSession.Connect());
    CleanupClosePushL(fileServerSession);

    TDriveList driveList;
    TChar driveLetter;
    TInt driveNumber = EDriveA;
    User::LeaveIfError(fileServerSession.DriveList(driveList));

    for (; driveNumber < KMaxDrives; driveNumber++)
        {

        if (driveList[driveNumber])
            {
            TChar aDrive;
            fileServerSession.DriveToChar(driveNumber, aDrive);
            TBuf<256> item;
            item.Format(_L(" %C:"), aDrive);
            //item就是磁盘标识符了。
            }
        }
    CleanupStack::PopAndDestroy();