MFC Remote Desktop ActiveX control interfaces with RedirectDynamicDrives

Hello,
I am trying to create Remote Desktop application using  CMstscax1 object.

The USB stick can display in client when I plug it before my instance starts,but can't realize plug and play

When my RDP instance starts,the drive redirection is not working when I plug in a USB stick. It works in normal RDP though (by mstsc.exe).

COleDispatchDriver disp;
	COleException *e = new COleException;

	if(disp.CreateDispatch(this->m_VSOConnector.GetClsid(), e))
	{
		IMsRdpClientNonScriptable3 * pNonScript = NULL;
		IUnknown* pUnknown = this->m_VSOConnector.GetControlUnknown();
		HRESULT hr=pUnknown->QueryInterface(IID_IMsRdpClientNonScriptable3,(void**)&pNonScript);
		if(SUCCEEDED(hr))
		{
			VARIANT_BOOL boolean = 0;
			pNonScript->put_RedirectDynamicDrives( VARIANT_TRUE );
			pNonScript->put_RedirectDynamicDevices( VARIANT_TRUE );

			pNonScript->get_ShowRedirectionWarningDialog(&boolean);

			pNonScript->get_RedirectDynamicDrives(&boolean);

			pNonScript->Release();

		} 
	}