R3中微软的Silverlight的例子XAMLPERF中的FRM_START,FRM_STOP,FRM_GET_FRAMES_PER_SECOND什么意思?

benz040 2010-3-30 10:03 楼主

这三个东西在main.cpp中定义的:
class FrameRateManager
{
enum FrameRateMonitorMessage
{
      FRM_START = 0,
      FRM_STOP,
      FRM_GET_FRAMES_PER_SECOND
};

使用如下:
//Register the message with the host
HRESULT RegisterMessage()
{
      HRESULT hr = S_OK;

      m_TestMessage = RegisterWindowMessage(c_FrameRateMessageName);
      CBR(0 != m_TestMessage);

      CHR(static_cast(SendMessage(m_Hwnd, m_TestMessage, FRM_START, 0)));
Error:
      return hr;
}

还有就是:
// get the current frame rate
HRESULT
GetFrameRate(UINT * pFPS)
{
      HRESULT hr = S_OK;
      DWORD ProcessId = NULL;

      HANDLE hRemoteProcess = NULL;
      VOID* pResultBuffer = NULL;
      float Result = 0.0;

      // Get a handle to the EXR process containing the target HWND
      GetWindowThreadProcessId(m_Hwnd, &ProcessId);
      hRemoteProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, ProcessId);

      // Allocate memory in the EXR process to marshal the fps counter over to this process
      pResultBuffer = VirtualAllocEx(hRemoteProcess, NULL, sizeof(FLOAT), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
      CPR(pResultBuffer);

      hr = static_cast(SendMessage(m_Hwnd, m_TestMessage, FRM_GET_FRAMES_PER_SECOND, (LPARAM)pResultBuffer));
      CHR(hr);

      // Read back EXR's response
      CBREx(ReadProcessMemory(hRemoteProcess, pResultBuffer, (LPVOID)(&Result), sizeof(FLOAT), NULL), GetLastErrorHR());

      if (pFPS)
      {
         *pFPS = (UINT)Result;
      }

Error:
      if (pResultBuffer)
      {
         VirtualFreeEx(hRemoteProcess, pResultBuffer, 0, MEM_RELEASE);
      }

      return hr;
}

=======================================================
CHR(static_cast(SendMessage(m_Hwnd, m_TestMessage, FRM_START, 0)));

hr = static_cast(SendMessage(m_Hwnd, m_TestMessage, FRM_GET_FRAMES_PER_SECOND, (LPARAM)pResultBuffer));

把这两个消息发出去,我看的比较迷茫一个.
我猜测这应该是Silverlight的内部实现的.但是MSDN中没有,不知道如何整.
资料太少了...水平不行啊...