开发环境：VS2012 + qt-opensource-windows-x86-msvc2012_opengl-5.4.0.exe + qt-vs-addin-1.2.5.exe
问题描述：使用QWebView基于百度地图的相关功能，在没有使用Direct3D之前功能一些正常，但是现在软件内另一个模块需要使用Direct3D渲染视频通话，结果地图这块就出问题了，加载异常缓慢，而且拖放等效果也慢的基本没法用，Direct3D我也不熟，照猫画虎，现在实在搞不清楚是什么问题，不知道有没有遇见过的给个指导。。。

这是初始化Direct3D的代码
IDirect3D9 *_d3d = Direct3DCreate9(D3D_SDK_VERSION);
if (_d3d == NULL)
{
return ;
}
D3DCAPS9 caps;
_d3d->GetDeviceCaps(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, &caps);
int vp = 0;
if (caps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT)
{
vp = D3DCREATE_HARDWARE_VERTEXPROCESSING;
}
else
{
vp = D3DCREATE_SOFTWARE_VERTEXPROCESSING;
}
D3DPRESENT_PARAMETERS d3dpp;//D3DPRESENT_PARAMETERS设置，设置IDirect3DDevice的特性
::ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS));
d3dpp.BackBufferWidth = 1920;
d3dpp.BackBufferHeight = 1080;
d3dpp.BackBufferFormat = D3DFMT_A8R8G8B8;
d3dpp.BackBufferCount = 1;
d3dpp.MultiSampleType = D3DMULTISAMPLE_NONE;
d3dpp.MultiSampleQuality = 0;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.hDeviceWindow = (HWND)AppHelper.mainWindow()->winId();
d3dpp.Windowed = TRUE;
d3dpp.EnableAutoDepthStencil = true;
d3dpp.AutoDepthStencilFormat = D3DFMT_D24S8;
d3dpp.Flags = 0;
d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT;
d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
IDirect3DDevice9* d3d_device;
if (_d3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, (HWND)AppHelper.mainWindow()->winId(), vp, &d3dpp, &d3d_device) != D3D_OK)
{
int i = 0;
return ;
}