C++怎么获取后台窗口内一点颜色值

Posted 2023-02-24

初学C++，请问怎么获取某一窗口内特定一点的颜色值，从后台获取，就是说这个窗口是最小化的，可以知道这个窗口句柄，以及这个点在窗口的坐标，不是屏幕上的点。谢谢

参考技术A 您好，winuser.h头文件中有所有系统颜色的宏定义，不妨在这里找您要的颜色：

/*
* Color Types
*/
#define CTLCOLOR_MSGBOX 0
#define CTLCOLOR_EDIT 1
#define CTLCOLOR_LISTBOX 2
#define CTLCOLOR_BTN 3
#define CTLCOLOR_DLG 4
#define CTLCOLOR_SCROLLBAR 5
#define CTLCOLOR_STATIC 6
#define CTLCOLOR_MAX 7
#define COLOR_SCROLLBAR 0
#define COLOR_BACKGROUND 1
#define COLOR_ACTIVECAPTION 2
#define COLOR_INACTIVECAPTION 3
#define COLOR_MENU 4
#define COLOR_WINDOW 5
#define COLOR_WINDOWFRAME 6
#define COLOR_MENUTEXT 7
#define COLOR_WINDOWTEXT 8
#define COLOR_CAPTIONTEXT 9
#define COLOR_ACTIVEBORDER 10
#define COLOR_INACTIVEBORDER 11
#define COLOR_APPWORKSPACE 12
#define COLOR_HIGHLIGHT 13
#define COLOR_HIGHLIGHTTEXT 14
#define COLOR_BTNFACE 15
#define COLOR_BTNSHADOW 16
#define COLOR_GRAYTEXT 17
#define COLOR_BTNTEXT 18
#define COLOR_INACTIVECAPTIONTEXT 19
#define COLOR_BTNHIGHLIGHT 20
#if(WINVER >= 0x0400)
#define COLOR_3DDKSHADOW 21
#define COLOR_3DLIGHT 22
#define COLOR_INFOTEXT 23
#define COLOR_INFOBK 24
#endif /* WINVER >= 0x0400 */
#if(WINVER >= 0x0500)
#define COLOR_HOTLIGHT 26
#define COLOR_GRADIENTACTIVECAPTION 27
#define COLOR_GRADIENTINACTIVECAPTION 28
#endif /* WINVER >= 0x0500 */
#if(WINVER >= 0x0400)
#define COLOR_DESKTOP COLOR_BACKGROUND
#define COLOR_3DFACE COLOR_BTNFACE
#define COLOR_3DSHADOW COLOR_BTNSHADOW
#define COLOR_3DHIGHLIGHT COLOR_BTNHIGHLIGHT
#define COLOR_3DHILIGHT COLOR_BTNHIGHLIGHT
#define COLOR_BTNHILIGHT COLOR_BTNHIGHLIGHT
#endif /* WINVER >= 0x0400 */

调用DWORD GetSysColor(int nIndex);函数，可以返回颜色的RGB值。追问

我是说窗口里一个点的颜色，比如窗口最小化后我相知道这个窗口里一点颜色

本回答被提问者采纳

C++ DirectX11 窗口颜色不变

【中文标题】C++ DirectX11 窗口颜色不变

【英文标题】：C++ DirectX11 Window Color not changing

【发布时间】：2017-08-10 18:48:48

【问题描述】：

我正在使用 DX11 开发游戏引擎。我正在关注http://www.rastertek.com/ 的教程。我已经完成了教程 2。问题是，当我尝试更改颜色值时，窗口仍然是黑色的。相关代码为：

Graphics.cpp

bool Graphics::Initialize(int screenWidth, int screenHeight, HWND hwnd)

    bool result;

    m_D3D = new D3DClass;

    if (!m_D3D)
        return false;

    result = m_D3D->Initialize(screenWidth, screenHeight, hwnd, VSYNC_ENABLED, FULL_SCREEN, SCREEN_DEPTH, SCREEN_NEAR);
    if (!result)
    
        MessageBox(hwnd, "Could not initialize Direct3D", "Error", MB_OK);
        return false;
    

    return true;


bool Graphics::Render()

    m_D3D->BeginScene(0.0f, 0.0f, 0.0f, 0.0f);
    m_D3D->EndScene();
    return true;

D3DClass.cpp

bool D3DClass::Initialize(int screenWidth, int screenHeight, HWND hwnd, bool vsync, bool fullscreen, float screenDepth, float screenNear)

    HRESULT result;
    IDXGIFactory* factory;
    IDXGIAdapter* adapter;
    IDXGIOutput* adapterOutput;
    unsigned int numModes, i, numerator, denominator, stringLength;
    DXGI_MODE_DESC* displayModeList;
    DXGI_ADAPTER_DESC adapterDesc;
    int error;
    DXGI_SWAP_CHAIN_DESC swapChainDesc;
    D3D_FEATURE_LEVEL featureLevel;
    ID3D11Texture2D* backBufferPtr;
    D3D11_TEXTURE2D_DESC depthBufferDesc;
    D3D11_DEPTH_STENCIL_DESC depthStencilDesc;
    D3D11_DEPTH_STENCIL_VIEW_DESC depthStencilViewDesc;
    D3D11_RASTERIZER_DESC rasterDesc;
    D3D11_VIEWPORT viewport;
    float fieldOfView, screenAspect;

    m_vsync_enabled = vsync;


    result = CreateDXGIFactory(__uuidof(IDXGIFactory), (void**)&factory);
    if (FAILED(result))
        return false;

    result = factory->EnumAdapters(0, &adapter);
    if (FAILED(result))
        return false;


    result = adapter->EnumOutputs(0, &adapterOutput);
    if (FAILED(result))
        return false;


    result = adapterOutput->GetDisplayModeList(DXGI_FORMAT_R8G8B8A8_UNORM, DXGI_ENUM_MODES_INTERLACED, &numModes, NULL);
    if (FAILED(result))
        return false;


    displayModeList = new DXGI_MODE_DESC[numModes];
    if (!displayModeList)
        return false;


    result = adapterOutput->GetDisplayModeList(DXGI_FORMAT_R8G8B8A8_UNORM, DXGI_ENUM_MODES_INTERLACED, &numModes, displayModeList);
    if(FAILED(result))
        return false;


    for (int i = 0; i < numModes; i++)
    
        if (displayModeList[i].Height == (unsigned int)screenHeight && displayModeList[i].Width == (unsigned int)screenWidth)
        
            numerator = displayModeList[i].RefreshRate.Numerator;
            denominator = displayModeList[i].RefreshRate.Denominator;
            break;
        
    


    result = adapter->GetDesc(&adapterDesc);
    if (FAILED(result))
        return false;


    m_videoCardMemory = (int)(adapterDesc.DedicatedVideoMemory / 1048576); //MB

    error = wcstombs_s(&stringLength, m_videoCardDescription, 128, adapterDesc.Description, 128);
    if (error != 0)
        return false;


    delete[] displayModeList;
    displayModeList = 0;

    adapterOutput->Release();
    adapterOutput = 0;

    adapter->Release();
    adapter = 0;

    factory->Release();
    factory = 0;


    ZeroMemory(&swapChainDesc, sizeof(swapChainDesc));
    swapChainDesc.BufferCount = 1;

    swapChainDesc.BufferDesc.Width = screenWidth;
    swapChainDesc.BufferDesc.Height = screenHeight;
    swapChainDesc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;

    if (m_vsync_enabled)
    
        swapChainDesc.BufferDesc.RefreshRate.Numerator = numerator;
        swapChainDesc.BufferDesc.RefreshRate.Denominator = denominator;
    
    else
    
        swapChainDesc.BufferDesc.RefreshRate.Numerator = 0;
        swapChainDesc.BufferDesc.RefreshRate.Denominator = 1;
    

    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swapChainDesc.OutputWindow = hwnd;

    //MultiSampling Off
    swapChainDesc.SampleDesc.Count = 1;
    swapChainDesc.SampleDesc.Quality = 0;

    swapChainDesc.Windowed = !fullscreen;

    swapChainDesc.BufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
    swapChainDesc.BufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;

    swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
    swapChainDesc.Flags = 0;

    featureLevel = D3D_FEATURE_LEVEL_11_0;

    result = D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, 0, &featureLevel, 1, D3D11_SDK_VERSION, &swapChainDesc, &m_swapChain, &m_device, NULL, &m_deviceContext);
    if (FAILED(result))
        return false;

    result = m_swapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&backBufferPtr);
    if (FAILED(result))
        return false;

    backBufferPtr->Release();
    backBufferPtr = 0;

    ZeroMemory(&depthBufferDesc, sizeof(depthBufferDesc));

    depthBufferDesc.Width = screenWidth;
    depthBufferDesc.Height = screenHeight;
    depthBufferDesc.MipLevels = 1;
    depthBufferDesc.ArraySize = 1;
    depthBufferDesc.Format = DXGI_FORMAT_D24_UNORM_S8_UINT;
    //Multisampling off
    depthBufferDesc.SampleDesc.Count = 1;
    depthBufferDesc.SampleDesc.Quality = 0;
    depthBufferDesc.Usage = D3D11_USAGE_DEFAULT;
    depthBufferDesc.BindFlags = D3D11_BIND_DEPTH_STENCIL;
    depthBufferDesc.CPUAccessFlags = 0;
    depthBufferDesc.MiscFlags = 0;

    result = m_device->CreateTexture2D(&depthBufferDesc, NULL, &m_depthStencilBuffer);
    if (FAILED(result))
        return false;


    ZeroMemory(&depthStencilDesc, sizeof(depthStencilDesc));
    depthStencilDesc.DepthEnable = true;
    depthStencilDesc.DepthWriteMask = D3D11_DEPTH_WRITE_MASK_ALL;
    depthStencilDesc.DepthFunc = D3D11_COMPARISON_LESS;
    depthStencilDesc.StencilEnable = true;
    depthStencilDesc.StencilReadMask = 0xFF;
    depthStencilDesc.StencilWriteMask = 0xFF;
    depthStencilDesc.FrontFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;
    depthStencilDesc.FrontFace.StencilDepthFailOp = D3D11_STENCIL_OP_INCR;
    depthStencilDesc.FrontFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;
    depthStencilDesc.FrontFace.StencilFunc = D3D11_COMPARISON_ALWAYS;
    depthStencilDesc.BackFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;
    depthStencilDesc.BackFace.StencilDepthFailOp = D3D11_STENCIL_OP_DECR;
    depthStencilDesc.BackFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;
    depthStencilDesc.BackFace.StencilFunc = D3D11_COMPARISON_ALWAYS;

    result = m_device->CreateDepthStencilState(&depthStencilDesc, &m_depthStencilState);
    if (FAILED(result))
        return false;


    m_deviceContext->OMSetDepthStencilState(m_depthStencilState, 1);

    ZeroMemory(&depthStencilViewDesc, sizeof(depthStencilViewDesc));
    depthStencilViewDesc.Format = DXGI_FORMAT_D24_UNORM_S8_UINT;
    depthStencilViewDesc.ViewDimension = D3D11_DSV_DIMENSION_TEXTURE2D;
    depthStencilViewDesc.Texture2D.MipSlice = 0;

    result = m_device->CreateDepthStencilView(m_depthStencilBuffer, &depthStencilViewDesc, &m_depthStencilView);
    if (FAILED(result))
        return false;

    m_deviceContext->OMSetRenderTargets(1, &m_renderTargetView, m_depthStencilView);

    //TODO::CUSTOMIZE USER PRESETS
    rasterDesc.AntialiasedLineEnable = false;
    rasterDesc.CullMode = D3D11_CULL_BACK;
    rasterDesc.DepthBias = 0;
    rasterDesc.DepthBiasClamp = 0.0f;
    rasterDesc.DepthClipEnable = true;
    rasterDesc.FillMode = D3D11_FILL_SOLID;
    rasterDesc.FrontCounterClockwise = false;
    rasterDesc.MultisampleEnable = false;
    rasterDesc.ScissorEnable = false;
    rasterDesc.SlopeScaledDepthBias = 0.0f;

    result = m_device->CreateRasterizerState(&rasterDesc, &m_rasterState);
    if (FAILED(result))
        return false;

    m_deviceContext->RSSetState(m_rasterState);

    viewport.Width = (float)screenWidth;
    viewport.Height = (float)screenHeight;
    viewport.MinDepth = 0.0f;
    viewport.MaxDepth = 1.0f;
    viewport.TopLeftX = 0.0f;
    viewport.TopLeftY = 0.0f;

    m_deviceContext->RSSetViewports(1, &viewport);

    //TODO:: FOV SETTINGS
    fieldOfView = (float)D3DX_PI / 4.0f;
    screenAspect = (float)screenWidth / (float)screenHeight;

    D3DXMatrixPerspectiveFovLH(&m_projectionMatrix, fieldOfView, screenAspect, screenNear, screenDepth);
    D3DXMatrixIdentity(&m_worldMatrix);
    D3DXMatrixOrthoLH(&m_orthoMatrix, (float)screenWidth, (float)screenHeight, screenNear, screenDepth);

    return true;

void D3DClass::BeginScene(float red, float green, float blue, float alpha)


    m_deviceContext->ClearRenderTargetView(m_renderTargetView, D3DXCOLOR(red, green, blue, alpha));

    m_deviceContext->ClearDepthStencilView(m_depthStencilView, D3D11_CLEAR_DEPTH, 1.0f, 0);
    return;


void D3DClass::EndScene()

    if (m_vsync_enabled)
        m_swapChain->Present(1, 0);
    else
        m_swapChain->Present(0, 0);

    return;

Framework.cpp

void Framework::InitializeWindows(int& screenWidth, int& screenHeight)

    WNDCLASSEX wc;
    DEVMODE dmScreenSettings;

    int posX, posY;

    m_application = this;
    m_hinstance = GetModuleHandle(NULL);

    m_applicationName = "Racing Game";

    wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = m_hinstance;
    wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
    wc.hIconSm = wc.hIcon;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = m_applicationName;
    wc.cbSize = sizeof(WNDCLASSEX);

    RegisterClassEx(&wc);

    screenWidth = GetSystemMetrics(SM_CXSCREEN);
    screenHeight = GetSystemMetrics(SM_CYSCREEN);

    if (FULL_SCREEN)
    
        memset(&dmScreenSettings, 0, sizeof(dmScreenSettings));
        dmScreenSettings.dmSize = sizeof(dmScreenSettings);
        dmScreenSettings.dmPelsWidth = (unsigned long)screenWidth;
        dmScreenSettings.dmPelsHeight = (unsigned long)screenHeight;
        dmScreenSettings.dmBitsPerPel = 32;
        dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;

        ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);

        posX = posY = 0;
    
    else
    
        screenWidth = 800;
        screenHeight = 600;

        posX = (GetSystemMetrics(SM_CXSCREEN) - screenWidth) / 2;
        posY = (GetSystemMetrics(SM_CYSCREEN) - screenHeight) / 2;
    

    m_hwnd = CreateWindowEx(WS_EX_APPWINDOW, m_applicationName, m_applicationName, WS_CLIPSIBLINGS | WS_CLIPCHILDREN | WS_POPUP, posX, posY, screenWidth, screenHeight, NULL, NULL, m_hinstance, NULL);
    ShowWindow(m_hwnd, SW_SHOW);
    SetForegroundWindow(m_hwnd);
    SetFocus(m_hwnd);

    ShowCursor(false);
    return;

每次我更改BeginScene() 调用中的参数时，无论是什么（我尝试了红色范围为 1.0f 到 256.0f 的值），窗口始终为黑色并且没有窗口顶部三个按钮（关闭、最小化、展开）。我究竟做错了什么？任何帮助表示赞赏。

【问题讨论】：

Rastertek 教程仍然有效，但它们使用了很多遗留的东西，所以请记住这一点。你可能想看看DirectX Tool Kit的教程

【参考方案1】：

我正在学习相同的教程，

0 到 1 之间的浮点数。

所以在你的情况下是红色的

bool Graphics::Render()

    m_D3D->BeginScene(1.0f, 0.0f, 0.0f, 1.0f);
    m_D3D->EndScene();
    return true;

不要忘记将 opacity 设置为最后一个值 1.0。

祝下一个好运。