支持扩展单元的自动更新事件

重要

本主题中的内容和示例代码已过时，目前不受支持。 它可能不适用于当前的驱动程序开发工具链。

本主题包含演示如何支持自动更新事件的示例代码。

在应用程序源中包含以下任意命名为 TestApp.cpp 的代码：

hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
if (!hEvent)
{
    printf("CreateEvent failed\n");
    goto errExit;
}
Event.Set = KSEVENTSETID_VIDCAPNotify;
Event.Id = KSEVENT_VIDCAP_AUTO_UPDATE;
Event.Flags = KSEVENT_TYPE_ENABLE;

EventData.NotificationType = KSEVENTF_EVENT_HANDLE;
EventData.EventHandle.Event = hEvent;
EventData.EventHandle.Reserved[0] = 0;
EventData.EventHandle.Reserved[1] = 0;

// register for autoupdate events
hr = m_pKsControl->KsEvent(
    &Event, 
 sizeof(KSEVENT), 
    &EventData, 
 sizeof(KSEVENTDATA), 
    &ulBytesReturned);
if (FAILED(hr))
{
    printf("Failed to register for auto-update event : %x\n", hr);
 goto errExit;
}

// Wait for event for 5 seconds 
dwError = WaitForSingleObject(hEvent, 5000);

// cancel further notifications
hr = m_pKsControl->KsEvent(
    NULL, 
    0, 
    &EventData, 
 sizeof(KSEVENTDATA), 
    &ulBytesReturned);
if (FAILED(hr))  printf("Cancel event returns : %x\n", hr);

if ((dwError == WAIT_FAILED) || 
   (dwError == WAIT_ABANDONED) ||
   (dwError == WAIT_TIMEOUT))
{
    printf("Wait failed : %d\n", dwError);
 goto errExit;
} 
printf("Wait returned : %d\n", dwError);

// handle the autoupdate event..