SetLayeredWindowAttributes 使窗口透明仅在部分时间起作用
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【中文标题】SetLayeredWindowAttributes 使窗口透明仅在部分时间起作用【英文标题】：SetLayeredWindowAttributes to make a window transparent is only working part of the time 【发布时间】：2013-08-25 08:59:41 【问题描述】：我正在尝试使窗口透明，以便只有部分内容可见，我尝试使用SetLayeredWindowAttributes 来实现这一点，这使窗口透明，但它只能以这种方式工作当窗口图片的一部分超出我桌面的可见区域时。出于某种原因，每当窗口完全显示在屏幕上时，它都会重新绘制其黑色背景（我用于透明的颜色，这意味着不可见。）Here 是该问题的视频示例。我不确定究竟是什么导致了这只是为了安全起见，我发布了完整的代码。
#define _WIN32_WINNT 0x501
#include "C:\Program Files\Microsoft DirectX SDK (August 2008)\Include\D3dx9core.h"
#include "C:\Documents and Settings\Death\My Documents\Downloads\DXSprite\DXSprite\resource.h"
#include <windows.h>
#include <string>
#include <stdio.h>
//-----------------------------------------------------------------------------
// GLOBALS
//-----------------------------------------------------------------------------
HWND g_hWnd = NULL;
LPDIRECT3D9 g_pD3D = NULL;
LPDIRECT3DDEVICE9 g_pD3DDevice = NULL;
ID3DXSprite * g_pD3DXSprite = NULL;
LPDIRECT3DTEXTURE9 g_pTexture = NULL;
const int SCREEN_WIDTH = 800;
const int SCREEN_HEIGHT = 600;
//-----------------------------------------------------------------------------
// PROTOTYPES
//-----------------------------------------------------------------------------
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
HRESULT InitializeD3D ( );
void RenderFrame ( );
//-----------------------------------------------------------------------------
// Name: WinMain()
// Desc: The application's entry point
//-----------------------------------------------------------------------------
int WINAPI WinMain( HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow )
WNDCLASSEX winClass;
MSG uMsg;
HRESULT hr;
memset(&uMsg,0,sizeof(uMsg));
winClass.lpszClassName = "MY_WINDOWS_CLASS";
winClass.cbSize = sizeof(WNDCLASSEX);
winClass.style = CS_HREDRAW | CS_VREDRAW;
winClass.lpfnWndProc = WindowProc;
winClass.hInstance = hInstance;
winClass.hIcon = LoadIcon(hInstance, (LPCTSTR)IDC_DXSPRITE);
winClass.hIconSm = LoadIcon(hInstance, (LPCTSTR)IDC_DXSPRITE);
winClass.hCursor = LoadCursor(NULL, IDC_ARROW);
winClass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
winClass.lpszMenuName = NULL;
winClass.cbClsExtra = 0;
winClass.cbWndExtra = 0;
if( !RegisterClassEx(&winClass) )
return E_FAIL;
g_hWnd = CreateWindowEx( WS_EX_LAYERED, "MY_WINDOWS_CLASS",
"Direct3D 9 - ID3DXSprite Example",
WS_OVERLAPPEDWINDOW | WS_VISIBLE ,
0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, NULL, NULL, hInstance, NULL );
if( g_hWnd == NULL )
return E_FAIL;
SetLayeredWindowAttributes(g_hWnd, RGB(0x00,0x00,0x00), 0, LWA_COLORKEY);
ShowWindow( g_hWnd, nCmdShow );
//----------------------------------------------------------------
// Create the DirectX device
//----------------------------------------------------------------
if (FAILED( InitializeD3D()))
return 0;
//----------------------------------------------------------------
// CREATE THE ID3DXSprite
//----------------------------------------------------------------
// Create the ID3DXSprite interface object
hr = D3DXCreateSprite(g_pD3DDevice, &g_pD3DXSprite );
if( FAILED(hr) )
return hr;
//----------------------------------------------------------------
// LOAD THE TEXTURE FOR THE SPRITE
//----------------------------------------------------------------
// --------------------------------------------------------
// Load the texture. I decided to use the extended
// version of the texture loading function just to show what
// it would look like.
// The texture was created with Photoshop with a transparent
// background to start with. Then line cross hairs were added.
//
// Note - If you don't use a texture image that has a power of
// 2 size for the width or height then the image may not load
// properly. This image is 256x256.
//
D3DXCreateTextureFromFileEx(
g_pD3DDevice,
"C:\\Documents and Settings\\Death\\My Documents\\45handold2.tga", // Our texture image!
D3DX_DEFAULT, // width
D3DX_DEFAULT, // height
D3DX_DEFAULT, // MIP levels
0, // usage
D3DFMT_DXT1, // texture format
D3DPOOL_MANAGED, // mem pool
D3DX_DEFAULT, // filter
D3DX_DEFAULT, // MIP filter
0, // transparent color key
NULL, // image info struct
NULL, // palette
&g_pTexture); // the returned texture, if success
if ( FAILED(hr) )
return hr;
// ---------
// Main Loop
// ---------
while( uMsg.message != WM_QUIT )
if( PeekMessage( &uMsg, NULL, 0, 0, PM_REMOVE ) )
TranslateMessage( &uMsg );
DispatchMessage( &uMsg );
// -------------------------
// Release directx resources
// -------------------------
if (g_pD3DXSprite)
g_pD3DXSprite->Release();
g_pD3DXSprite = NULL;
if (g_pTexture)
g_pTexture->Release();
g_pTexture = NULL;
if (g_pD3DDevice)
g_pD3DDevice->Release();
g_pD3DDevice = NULL;
UnregisterClass( "MY_WINDOWS_CLASS", winClass.hInstance );
return (int)uMsg.wParam;
//-----------------------------------------------------------------------------
// Name: WindowProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
LRESULT CALLBACK WindowProc( HWND hWnd,
UINT msg,
WPARAM wParam,
LPARAM lParam )
switch( msg )
case WM_KEYDOWN:
switch( wParam )
case VK_ESCAPE:
PostQuitMessage(0);
break;
break;
case WM_CLOSE:
PostQuitMessage(0);
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
RenderFrame();
return DefWindowProc( hWnd, msg, wParam, lParam );
break;
return 0;
//-----------------------------------------------------------------------------
// Name: InitializeD3D()
// Desc: Create DirectX interface objects
// Initialize the view matrix.
// Setup render states that will not need changing throughout
// the life of the application.
//-----------------------------------------------------------------------------
HRESULT InitializeD3D( )
HRESULT hr;
// Create a direct 3D interface object
g_pD3D = Direct3DCreate9( D3D_SDK_VERSION );
if( g_pD3D == NULL )
// TO DO: Respond to failure of Direct3DCreate9
return E_FAIL;
D3DDISPLAYMODE d3ddm;
if( FAILED( hr = g_pD3D->GetAdapterDisplayMode( D3DADAPTER_DEFAULT, &d3ddm ) ) )
// TO DO: Respond to failure of GetAdapterDisplayMode
return hr;
//
if( FAILED( hr = g_pD3D->CheckDeviceFormat( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL,
d3ddm.Format, D3DUSAGE_DEPTHSTENCIL,
D3DRTYPE_SURFACE, D3DFMT_D16 ) ) )
if( hr == D3DERR_NOTAVAILABLE )
// POTENTIAL PROBLEM: We need at least a 16-bit z-buffer!
return hr;
//
// Do we support hardware vertex processing? If so, use it.
// If not, downgrade to software.
//
D3DCAPS9 d3dCaps;
if( FAILED( hr = g_pD3D->GetDeviceCaps( D3DADAPTER_DEFAULT,
D3DDEVTYPE_HAL, &d3dCaps ) ) )
// TO DO: Respond to failure of GetDeviceCaps
return hr;
DWORD dwBehaviorFlags = 0;
if( d3dCaps.VertexProcessingCaps != 0 )
dwBehaviorFlags |= D3DCREATE_HARDWARE_VERTEXPROCESSING;
else
dwBehaviorFlags |= D3DCREATE_SOFTWARE_VERTEXPROCESSING;
//
// Everything checks out - create a simple, windowed device.
//
D3DPRESENT_PARAMETERS d3dpp;
memset(&d3dpp, 0, sizeof(d3dpp));
d3dpp.BackBufferFormat = d3ddm.Format;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.Windowed = TRUE;
d3dpp.EnableAutoDepthStencil = TRUE;
d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
// Attempt to create a HAL device, end app on failure just to keep things
// simple. In other words we are not trying to create a REF device if the
// HAL fails.
if( FAILED( hr = g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, g_hWnd,
dwBehaviorFlags, &d3dpp, &g_pD3DDevice ) ) )
// char blah[100];
// snprintf (blah, 1000, "%d", hr);
//MessageBox (NULL,blah,NULL,NULL);
// If we get here everything worked!
return S_OK;
//-----------------------------------------------------------------------------
// Name: RenderFrame()
// Desc: Draw the image to the framebuffer.
//-----------------------------------------------------------------------------
void RenderFrame( )
if (!g_pD3DDevice && !g_pD3DXSprite && !g_pTexture)
return;
// Clear the frame & depth buffer ready for drawing (Black color)
g_pD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00000000, 1.0f, 0 );
g_pD3DDevice->BeginScene();
//-------------------------
// Render the sprite
//
D3DXVECTOR3 vecPos = D3DXVECTOR3(0,0,0);
if (g_pD3DXSprite && g_pTexture)
g_pD3DXSprite->Begin( D3DXSPRITE_ALPHABLEND );
g_pD3DXSprite->Draw(g_pTexture, NULL, NULL, &vecPos, 0xffffffff);
g_pD3DXSprite->End();
g_pD3DDevice->EndScene();
// Frame buffer to Front buffer
g_pD3DDevice->Present( NULL, NULL, NULL, NULL );
【问题讨论】：
【参考方案1】：您遇到的问题基本上是在 Windows 中曾经有两个完全独立的渲染堆栈：GDI 和 Direct3D。他们根本没有真正互相交谈，因此标准窗口和 GDI API 对 Direct3D 并不真正了解。当 Vista 出现时，他们统一了两个驱动程序堆栈，但 GDI 代码（一般而言）仍然对 Direct3D 一无所知，即使它在内部使用了一些幕后的 Direct3D（用于桌面合成）。
简而言之，SetLayeredWindowAttributes 和 UpdateLayeredWindow 不能也不知道您的 Direct3D 交换链。如果您在 Windows XP 或 2000 上尝试过这个，我希望您会得到一些非常时髦的视觉效果。我应该补充一下，这有一些非常好的理由。例如，在 GDI 世界中，使用UpdateLayeredWindow 设置具有每像素 alpha 的位图实际上会导致 alpha 值为零的位置被视为不属于窗口的一部分。换句话说，点击会传递到下面的窗口。为了使用 Direct3D 实现这一点，系统必须将 Direct3D 纹理从 GPU 读回 CPU 内存，这非常昂贵，然后执行命中测试。
当然，一种解决方案是使用 GDI 来渲染窗口，包括颜色键。我假设您出于性能原因排除了这一点。
我不完全确定您所期望的视觉效果，但如果您想在具有完全硬件加速且没有窗口边框的窗口中呈现任意 alpha 混合内容，您可以创建一个无边框窗口（例如，仅 WS_POPUP为其窗口样式）并调用 DwmExtendFrameIntoClientArea 为所有边距传递 -1。然后，使用 D3DFMT_A8R8G8B8 像素格式或 Direct3D 10/11 的 DXGI 等效格式（这是 DWM 用于渲染窗口的本机格式）创建交换链并渲染到其中。您现在拥有一个仅包含叠加在桌面上的 alpha 混合内容的窗口。有一个关于这个主题的older article on CodeProject。
【讨论】：
我在 windows XP 上，所以 DwmExtendFrameintoClientArea 对我来说是不可能的（它支持的最低客户端是 windows vista。）以上是关于SetLayeredWindowAttributes 使窗口透明仅在部分时间起作用的主要内容，如果未能解决你的问题，请参考以下文章