如何提取COM消息？

简而言之,你必须正常地输出所有消息,你不能自己单独输出COM消息(此外,没有记录的消息,你可以自己查看/泵浦,他们只知道COM的内部).

如何使WebBrower.Navigate2同步？

你不能.但是你也不必等待这个OnDocumentComplete事件.你可以在NavigateToEmpty()自己内部忙碌循环,直到WebBrowser的ReadyState属性为止READYSTATE_COMPLETE,在等待处理消息时抽取消息队列:

procedure TContoso.NavigateToEmpty(WebBrowser: IWebBrowser2);
begin
  WebBrowser.Navigate2('about:blank');
  while (WebBrowser.ReadyState <> READYSTATE_COMPLETE) and (not Application.Terminated) do
  begin
    // if MsgWaitForMultipleObjects(0, Pointer(nil)^, False, 5000, QS_ALLINPUT) = WAIT_OBJECT_0 then
    // if GetQueueStatus(QS_ALLINPUT) <> 0 then
      Application.ProcessMessages;
  end;
end;

如何提取COM消息？

无论如何,你不能,不能自己.泵送一切,并准备好处理由此产生的任何再入问题.

抽COM消息会导致COM事件回调吗？

是.

如何使用CoWaitForMultipleHandles

尝试这样的事情:

procedure TContoso.NavigateToEmpty(WebBrowser: IWebBrowser2);
var
  hEvent: THandle;
  dwIndex: DWORD;
  hr: HRESULT;
begin
  // when UseCOMWait() is true, TEvent.WaitFor() does not wait for, or
  // notify, when messages are pending in the queue, so use
  // CoWaitForMultipleHandles() directly instead.  But you have to still
  // use a waitable object, just don't signal it...
  hEvent := CreateEvent(nil, True, False, nil);
  if hEvent = 0 then RaiseLastOSError;
  try
    WebBrowser.Navigate2('about:blank');
    while (WebBrowser.ReadyState <> READYSTATE_COMPLETE) and (not Application.Terminated) do
    begin
      hr := CoWaitForMultipleHandles(COWAIT_INPUTAVAILABLE, 5000, 1, hEvent, dwIndex);
      case hr of
        S_OK: Application.ProcessMessages;
        RPC_S_CALLPENDING, RPC_E_TIMEOUT: begin end;
      else
        RaiseLastOSError(hr);
      end;
    end;
  finally
    CloseHandle(hEvent);
  end;
end;