擷取裝置屬性

[與此頁面相關聯的功能Windows 媒體播放機 SDK是舊版功能。 MediaPlayer已取代它。 MediaPlayer已針對Windows 10和Windows 11進行優化。 Microsoft 強烈建議新程式碼盡可能使用MediaPlayer，而不是Windows 媒體播放機 SDK。 Microsoft 建議使用舊版 API 的現有程式碼盡可能重寫為使用新的 API。

Windows 媒體播放機儲存已連線到播放機之裝置的相關資訊。 某些屬性可藉由呼叫 IWMPSyncDevice的個別方法取得，有些屬性可以使用 IWMPSyncDevice：：getItemInfo來擷取，而有些則可以使用任一技術來擷取。

下列範例程式碼會以指定裝置的可用屬性填入清單方塊控制項。 函式的第一個部分會擷取使用特定方法可用的屬性。 函式的第二個部分會使用 IWMPSyncDevice：：getItemInfo來擷取屬性值。 函式參數 lIndex是m_ppWMPDevices所指向之自訂裝置陣列中裝置的索引。

STDMETHODIMP CMainDlg::ShowDeviceAttributes(long lIndex)
{
    HRESULT hr = S_OK;

    if(!m_ppWMPDevices)
        return S_FALSE;

    // Array of attribute names for devices.
    const TCHAR *szDeviceAttributeNames[16] = {
    _T("Connected"),
    _T("FreeSpace"),
    _T("FriendlyName"),
    _T("LastSyncErrorCount"),
    _T("LastSyncNoFitCount"),
    _T("LastSyncTime"),
    _T("Name"),
    _T("SerialNumber"),
    _T("SupportsAudio"),
    _T("SupportsPhoto"),
    _T("SupportsVideo"),
    _T("SyncIndex"),
    _T("SyncItemCount"),
    _T("SyncPercentComplete"),
    _T("SyncRelationship"),
    _T("TotalSpace")};
    
    // Array of device status strings.
    static const TCHAR *szDeviceStatus[6] = {
    _T("Unknown"),
    _T("Partnership exists"),
    _T("Partnership declined by the user"),
    _T("Partnership with another computer or user"),
    _T("Device only supports manual transfer"),
    _T("New device")};

    // Handle to the list box that displays the information.
    HWND hwndStats = GetDlgItem(IDC_STATS);
    CComBSTR bstrStatistics;  // Contains the display string for each property.
    CComBSTR bstrTemp; // Contains the retrieved value for each property.
    // Retrieve a pointer to the current device.
    CComPtr<IWMPSyncDevice> spDevice(m_ppWMPDevices[GetSelectedDeviceIndex()]);
    VARIANT_BOOL vbIsConnected = VARIANT_FALSE;
    WMPDeviceStatus  wmpDS = wmpdsUnknown;
    
    SendMessage(hwndStats, LB_RESETCONTENT, 0, 0);

    if(NULL == spDevice.p)
    {
        return E_POINTER;
    }
 
    // Status
    spDevice->get_status(&wmpDS);
    bstrStatistics = "Status: ";
    bstrTemp = szDeviceStatus[wmpDS];
    bstrStatistics += bstrTemp;
    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics)); 
    bstrTemp.Empty();
    
    // Connected?
    spDevice->get_connected(&vbIsConnected);
    bstrStatistics = "Connected: ";
    bstrTemp = (vbIsConnected == VARIANT_TRUE)?"True":"False";
    bstrStatistics += bstrTemp;
    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics));
    bstrTemp.Empty();
    
    // Device ID
    spDevice->get_deviceId(&bstrTemp);
    bstrStatistics = "Device ID: ";
    bstrStatistics += bstrTemp;

    // Calculate the list box width based on text metrics.
    // This assumes Device ID is likely to be the longest string.
    HDC hDC = GetDC();
    SIZE sizeText = {0, 0};
    GetTextExtentPoint32(hDC, (LPCTSTR)COLE2T(bstrStatistics), bstrStatistics.Length(), &sizeText);
    ReleaseDC(hDC);

    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics)); 
    SendMessage(hwndStats, LB_SETHORIZONTALEXTENT, sizeText.cx, 0);
    bstrTemp.Empty();

    // Friendly name
    spDevice->get_friendlyName(&bstrTemp);
    bstrStatistics = "Friendly name: ";
    bstrStatistics += bstrTemp;
    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics)); 
    bstrTemp.Empty();

    // Skip a line and label the getItemInfo attributes.
    bstrStatistics = "";
    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics)); 
    bstrStatistics = "--getItemInfo Attributes--";
    SendMessage(hwndStats, LB_ADDSTRING, 0,(LPARAM)(LPCTSTR)COLE2T(bstrStatistics)); 

    // Show the getItemInfo attributes.
    int iArrayBound = sizeof szDeviceAttributeNames / sizeof szDeviceAttributeNames[0];
    for(int i = 0; i < iArrayBound; i++)
    {
        CComBSTR bstrName(szDeviceAttributeNames[i]);
        CComBSTR bstrVal;
        CComBSTR bstrDisplayString;
       
        hr = spDevice->getItemInfo(bstrName, &bstrVal);
  
        if(FAILED(hr))
        {
             bstrVal.Append("Error");
        }  
        
        bstrName.Append(L": ");
        bstrDisplayString.AppendBSTR(bstrName);
        bstrDisplayString += bstrVal;  
 
        SendMessage(hwndStats, LB_ADDSTRING, 0, (LPARAM)(LPCTSTR)COLE2T(bstrDisplayString));
    }    

    return hr;
}

相關主題

列舉裝置

IWMPSyncDevice 介面

IWMPSyncDevice：：getItemInfo

使用可攜式裝置