Showing Synchronization Progress

[The feature associated with this page, Windows Media Player SDK, is a legacy feature. It has been superseded by MediaPlayer. MediaPlayer has been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer instead of Windows Media Player SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

You can display synchronization progress to the user. The following example code shows how to create a timer to periodically retrieve the current progress value by using IWMPSyncDevice::get_progress. Note that the progress value retrieved represents the progress for the entire synchronization operation for each device. Retrieving synchronization progress for individual media items is not supported.

To determine when to start or stop the timer, handle the DeviceSyncStateChange event. The following example function demonstrates such an event handler. The code also displays the current synchronization state as a text string using a static text control, named IDC_SYNCSTATE.

void CMainDlg::DeviceSyncStateChange( IWMPSyncDevice * pDevice, WMPSyncState NewState )
{
    if(NULL == pDevice)
    {
        return;
    }

    HRESULT hr = E_POINTER;
    VARIANT_BOOL  vbIdentical = VARIANT_FALSE;
    // Window handle for static text control that shows the sync state.
    HWND hwndSyncStateText = GetDlgItem(IDC_SYNCSTATE); 

    // Strings to show sync state.
    const TCHAR *szSyncState[3] = {
    _T("Unknown"),
    _T("Synchronizing"),
    _T("Stopped")};

    // Get a pointer to the device the user selected in the list box.    
    CComPtr<IWMPSyncDevice> spDevice(m_ppWMPDevices[GetSelectedDeviceIndex()]); 
    // Cache the pointer to the device that raised the event.
    CComPtr<IWMPSyncDevice> spDeviceParam(pDevice); 

    if(spDevice.p)
    {
        // Test whether the device that raised the event is the same as 
        // the one the user selected.
        hr = spDevice->isIdentical(spDeviceParam, &vbIdentical);
    }

    if(SUCCEEDED(hr) &&
        vbIdentical == VARIANT_TRUE)
    {    
        // Display the sync state.
        SendMessage(hwndSyncStateText, WM_SETTEXT, 0, (LPARAM)szSyncState[NewState]);

        switch(NewState)
        {
        case wmpssSynchronizing:
            // Start the progress timer.
            SetTimer(1, 1000, NULL);
            SetUIState(Synchronizing, TRUE);
            break;
        case wmpssStopped:
            // Stop the progress timer.
            KillTimer(1);
            // Make sure the final progress is displayed.            
            ShowProgress(GetSelectedDeviceIndex());
            SetUIState(Partnership, TRUE);
            break;      
        default:
            break;
        }
    }    
}

When the timer is running, it sends a WM_TIMER message at one-second intervals. The application handles WM_TIMER in its message loop.

The following example function demonstrates how to show progress by using both a static text control (IDC_PROGSTATIC), and using a progress control (IDC_SYNCPROG). Call this function in response to the WM_TIMER message and upon completion of the synchronization process, as shown in the preceding example.

STDMETHODIMP CMainDlg::ShowProgress(long lIndex)
{  
    ATLASSERT(m_ppWMPDevices);

    long lProgress = 0;
    WCHAR buffer[10]; // Buffer larger than needed to hold progress string.
    ZeroMemory(buffer, sizeof WCHAR * 10);

    // Retrieve a handle to the progress control
    HWND  hwndSyncProgressCtl = GetDlgItem(IDC_SYNCPROG); 
    // Retrieve a handle to the static control that displays 
    // progress as text.
    HWND  hwndSyncProgressText = GetDlgItem(IDC_PROGSTATIC); 

    CComPtr<IWMPSyncDevice> spDevice(m_ppWMPDevices[lIndex]);
    
    HRESULT hr = spDevice->get_progress(&lProgress);

    // Convert progress to a string and add the percent character.
    _ltow(lProgress, buffer, 10);
    CComBSTR bstrProgress(buffer);
    bstrProgress += " %";

    // Display the text.
    ::SendMessage(hwndSyncProgressText, WM_SETTEXT, 0, (LPARAM)(LPCTSTR)COLE2T(bstrProgress));
    // Set the progress control position.
    ::SendMessage(hwndSyncProgressCtl, PBM_SETPOS, (WPARAM)(int)lProgress, 0);

    return hr;
}

Related topics

Enumerating Devices

IWMPSyncDevice Interface

IWMPSyncDevice::get_progress

IWMPSyncDevice::isIdentical

Working with Portable Devices