带有阴影的无边框窗口

Question

我试图通过无边框窗口和投影实现Visual Studio安装程序：

我尝试了各种选项，例如CS_DROPSHADOW和DWM API，但只要应用WS_THICKFRAME样式，阴影就会消失。

这是我创建和居中窗口的代码：

RECT R = {0, 0, _clientWidth, _clientHeight};
AdjustWindowRect(&R, WS_OVERLAPPEDWINDOW, false);
_mainWnd = CreateWindow(L"D3DWndClassName", _mainWndCaption.c_str(), WS_OVERLAPPEDWINDOW, 100, 100, R.right, R.bottom, nullptr, nullptr, _appInst, nullptr);

if(!_mainWnd){
    MessageBox(nullptr, L"CreateWindow FAILED", nullptr, 0);
    PostQuitMessage(0);
}

RECT rc;

GetWindowRect(_mainWnd, &rc);

LONG lStyle = GetWindowLong(_mainWnd, GWL_STYLE);
lStyle &= ~(WS_CAPTION | WS_THICKFRAME | WS_MINIMIZE | WS_MAXIMIZE | WS_SYSMENU );
SetWindowLong(_mainWnd, GWL_STYLE, lStyle);


int xPos = (GetSystemMetrics(SM_CXSCREEN) - rc.right) / 2;
int yPos = (GetSystemMetrics(SM_CYSCREEN) - rc.bottom) / 2;

SetWindowPos(_mainWnd, 0, xPos, yPos, _clientWidth, _clientHeight, SWP_NOZORDER);

ShowWindow(_mainWnd, SW_SHOW);
UpdateWindow(_mainWnd);