我的系统是Windows 7,我想将Direct2D用于工具包项目。
我想在窗口的某些部分中创建一个按像素透明/半透明的窗口(我们可以看到透明或半透明的窗口,这些窗口在我的窗口下方)。
我看过https://docs.microsoft.com/en-us/archive/msdn-magazine/2014/june/windows-with-c-high-performance-window-layering-using-the-windows-composition-engine(请参阅此网页最底部的图像),似乎有可能,但只能使用扩展的窗口样式WS_EX_NOREDIRECTIONBITMAP,该样式在Win7上不可用(仅从win8起)。
我尝试使用的渲染目标是带有预乘alpha的bgra和扩展的窗口样式WS_EX_COMPOSITED | WS_EX_TRANSPARENT没有运气
这是我的代码(相关的代码,即渲染目标和布局的创建,位于render()函数中):
#include <iostream>
#ifdef _WIN32_WINNT
# undef _WIN32_WINNT
#endif
#define _WIN32_WINNT 0x602
#include <d2d1.h>
static HINSTANCE instance = NULL;
static HWND win = NULL;
static ID2D1Factory *factory = NULL;
static ID2D1HwndRenderTarget *rt = NULL;
LRESULT CALLBACK _window_procedure(HWND window,
UINT message,
WPARAM window_param,
LPARAM data_param);
static void
render()
{
RECT r;
HRESULT res;
/* render target */
GetClientRect(win, &r);
D2D1_SIZE_U size = D2D1::SizeU(r.right, r.bottom);
FLOAT dpix;
FLOAT dpiy;
factory->GetDesktopDpi(&dpix, &dpiy);
D2D1_RENDER_TARGET_PROPERTIES rtp;
rtp.type = D2D1_RENDER_TARGET_TYPE_DEFAULT;
rtp.pixelFormat.format = DXGI_FORMAT_B8G8R8A8_UNORM;
rtp.pixelFormat.alphaMode = D2D1_ALPHA_MODE_PREMULTIPLIED;
rtp.dpiX = dpix;
rtp.dpiY = dpiy;
rtp.usage = D2D1_RENDER_TARGET_USAGE_NONE;
rtp.minLevel = D2D1_FEATURE_LEVEL_10;
D2D1_HWND_RENDER_TARGET_PROPERTIES wrtp;
wrtp.hwnd = win;
wrtp.pixelSize = size;
wrtp.presentOptions = D2D1_PRESENT_OPTIONS_IMMEDIATELY;
res =factory->CreateHwndRenderTarget(rtp, wrtp, &rt);
if (FAILED(res))
{
std::cout << "CreateHwndRenderTarget failed" << std::endl;
return;
}
/* brush */
ID2D1SolidColorBrush *brush;
/* rgba */
const D2D1_COLOR_F color = D2D1::ColorF(0.5, 0.5, 0, 0.5);
res = rt->CreateSolidColorBrush(color, &brush);
if (FAILED(res))
{
std::cout << "CreateSolidColorBrush failed" << std::endl;
return;
}
/* ellipse */
D2D1_ELLIPSE ellipse;
D2D1_SIZE_F sz = rt->GetSize();
const float x = sz.width / 2;
const float y = sz.height / 2;
const float radius = std::min(x, y);
ellipse = D2D1::Ellipse(D2D1::Point2F(x, y), radius, radius);
rt->BeginDraw();
rt->Clear( D2D1::ColorF(D2D1::ColorF::SkyBlue, 0.5f) );
rt->FillEllipse(ellipse, brush);
rt->EndDraw();
}
LRESULT CALLBACK
_window_procedure(HWND window,
UINT message,
WPARAM window_param,
LPARAM data_param)
{
switch (message)
{
case WM_CLOSE:
PostQuitMessage(0);
return 0;
case WM_KEYUP:
if (window_param == 'Q')
{
PostQuitMessage(0);
}
return 0;
/* GDI notifications */
case WM_PAINT:
{
RECT rect;
std::cout << "paint" << std::endl;
if (GetUpdateRect(window, &rect, FALSE))
{
PAINTSTRUCT ps;
BeginPaint(window, &ps);
render();
EndPaint(window, &ps);
}
return 0;
}
default:
return DefWindowProc(window, message, window_param, data_param);
}
}
int main()
{
/* class */
WNDCLASS wc;
instance = GetModuleHandle(NULL);
if (!instance)
return 1;
memset (&wc, 0, sizeof (WNDCLASS));
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = _window_procedure;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = instance;
wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(1 + COLOR_BTNFACE);
wc.lpszMenuName = NULL;
wc.lpszClassName = "D2D";
if(!RegisterClass(&wc))
goto free_library;
/* Window */
int w;
int h;
RECT r;
DWORD style;
DWORD exstyle;
w = 640;
h = 480;
style = WS_OVERLAPPEDWINDOW | WS_SIZEBOX;
exstyle = 0;
exstyle |= WS_EX_COMPOSITED | WS_EX_TRANSPARENT;
//exstyle |= WS_EX_NOREDIRECTIONBITMAP;
r.left = 0;
r.top = 0;
r.right = w;
r.bottom = h;
if (!AdjustWindowRectEx(&r, style, FALSE, exstyle))
goto unregister_class;
win = CreateWindowEx(exstyle,
"D2D", "Test",
style,
100, 100,
r.right - r.left,
r.bottom - r.top,
NULL,
NULL, instance, NULL);
if (!win)
goto unregister_class;
ShowWindow(win, SW_SHOWNORMAL);
/* factory */
if (FAILED(D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED,
&factory)))
goto destroy_win;
/* msg loop */
while(1)
{
MSG msg;
BOOL ret;
ret = PeekMessage(&msg, NULL, 0, 0, PM_REMOVE);
if (ret)
{
do
{
if (msg.message == WM_QUIT)
goto beach;
TranslateMessage(&msg);
DispatchMessageW(&msg);
} while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE));
}
}
beach:
factory->Release();
DestroyWindow(win);
UnregisterClass("D2D", instance);
FreeLibrary(instance);
return 0;
destroy_win:
DestroyWindow(win);
unregister_class:
UnregisterClass("D2D", instance);
free_library:
FreeLibrary(instance);
return 1;
}
我也不想使用分层窗口。
有人知道在Windows 7上是否可以实现我想要的吗?
谢谢
答案 0 :(得分:0)
在 Win7 上可以有一个没有 WS_EX_LAYERED
样式的透明窗口,但它有一些缺点:
window 必须有 WS_POPUP
样式,否则如果 Windows 样式有玻璃,窗口的背景会模糊。
windows上的DWM(Desktop Window Manager)必须开启,否则windows会不透明
虽然窗口在视觉上是透明的,但鼠标点击不会穿过 100% 透明区域。也许有解决方案,但我不知道。
// Transparent window setup
#include <dwmapi.h>
#pragma comment(lib, "Dwmapi")
// ....
MARGINS margins = { -1 };
DwmExtendFrameIntoClientArea(m_hwnd, &margins);
if (FAILED(D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &pFactory)))
{
return -1;
}
// ...
hr = pFactory->CreateHwndRenderTarget(
D2D1::RenderTargetProperties(
D2D1_RENDER_TARGET_TYPE_DEFAULT
, D2D1::PixelFormat(DXGI_FORMAT_UNKNOWN, D2D1_ALPHA_MODE_PREMULTIPLIED)
)
, D2D1::HwndRenderTargetProperties(m_hwnd, size)
, &pRenderTarget
);
如果您的窗口不透明,您可能关闭了 DWM 或 Windows 没有设置区域样式。
https://weblogs.asp.net/kennykerr/direct2d-and-the-desktop-window-manager