C/C++实现透明窗口程序

港控/mmm° 2024-03-16 11:00 57阅读 0赞

> 本文介绍几种在Windows环境下通过C/C++使用WIN32API实现透明窗口的方法。如有问题，请私信或者在评论区评论。

## 一、透明窗口实现 ##

### 1. 方式一 ###

通过 `SetLayeredWindowAttributes` 函数实现，需要添加以下代码：

// 设置窗口透明度
    SetLayeredWindowAttributes(
    	hWnd,       // 窗口句柄
    	0,          // 需要透明化的颜色值，0表示不使用颜色值
    	128,        // 透明度，取值为0-255
    	LWA_ALPHA   // 指定透明度效果
    );

以下为完整示例代码：

#include <Windows.h>
    
    LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
        
        switch (message)
        {
        
        case WM_DESTROY:
        {
        
            PostQuitMessage(0);
            break;
        }
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
        }
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow)
    {
        
        // 定义窗口类
        const wchar_t CLASS_NAME[] = L"MyWindowClass";
        WNDCLASSEX wc = {
         0 };
        wc.cbSize = sizeof(wc);                         
        wc.lpfnWndProc = WindowProc;                  
        wc.lpszClassName = CLASS_NAME;
        wc.style = CS_HREDRAW | CS_VREDRAW;
        wc.hCursor = LoadCursor(NULL, IDC_ARROW);
        wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
        wc.cbWndExtra = sizeof(LONG_PTR);
        wc.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
        wc.hIconSm = LoadIcon(hInstance, IDI_APPLICATION);
        wc.hInstance = hInstance;
        wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
        wc.cbClsExtra = 0;
        wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    
        // 注册窗口
        RegisterClassEx(&wc);
    
        // 创建窗口
        HWND hWnd = CreateWindowEx(
            WS_EX_LAYERED,                  
            CLASS_NAME,                     
            "透明窗口", 
            WS_OVERLAPPEDWINDOW,           
            CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
            NULL,       
            NULL,       
            hInstance,  
            NULL        
        );
        // 创建失败
        if (hWnd == NULL)
        {
        
            return -1;
        }
    
        // 设置窗口透明度
        SetLayeredWindowAttributes(
            hWnd,       // 窗口句柄
            0,          // 颜色键
            128,        // 透明度，取值为0-255
            LWA_ALPHA   // 
        );
    
        // 显示窗口
        ShowWindow(hWnd, nCmdShow);
    
        // 消息循环
        MSG msg = {
         0 };
        while (GetMessage(&msg, NULL, 0, 0))
        {
        
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    
        return 0;
    }

### 2. 方式二 ###

使用 `SetWindowLong()` 和 `SetLayeredWindowAttributes()` 函数实现透明窗口。

完整示例代码如下：

#include <windows.h>
    
    LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
    {
        
        switch (msg)
        {
        
        case WM_CREATE:  // 多用于窗口的初始化
            // 设置窗口扩展样式为WS_EX_LAYERED
            SetWindowLong(hWnd, GWL_EXSTYLE, GetWindowLong(hWnd, GWL_EXSTYLE) | WS_EX_LAYERED);
            // 设置窗口透明度为50%（0-255，255为完全不透明）
            SetLayeredWindowAttributes(hWnd, 0, 128, LWA_ALPHA);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hWnd, msg, wParam, lParam);
        }
        return 0;
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
    {
        
        const char *CLASS_NAME = "MyClass";
    
        WNDCLASS wc = {
        0};
        wc.lpfnWndProc = WndProc;
        wc.hInstance = hInstance;
        wc.lpszClassName = CLASS_NAME;
        RegisterClass(&wc);
    
        HWND hWnd = CreateWindowEx(WS_EX_LAYERED, CLASS_NAME, "Transparent Window", WS_OVERLAPPEDWINDOW,
                                   CW_USEDEFAULT, CW_USEDEFAULT, 400, 300, NULL, NULL, hInstance, NULL);
        
        ShowWindow(hWnd, nCmdShow);
    
        MSG msg;
        while (GetMessage(&msg, NULL, 0, 0))
        {
        
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    
        return 0;
    }

### 3. 方式三 ###

使用 `UpdateLayeredWindow()` 函数实现透明窗口，完整实例代码如下：

#include <windows.h>
    
    LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
    {
        
        switch (msg)
        {
        
        case WM_CREATE:
        {
        
            // 创建窗口的设备上下文
            HDC hdc = GetDC(hWnd);
    
            // 创建透明位图
            int width = 400;
            int height = 300;
            HBITMAP hBitmap = CreateCompatibleBitmap(hdc, width, height);
    
            // 创建与位图相关联的设备上下文
            HDC hdcMem = CreateCompatibleDC(hdc);
            SelectObject(hdcMem, hBitmap);
    
            // 绘制透明背景
            BLENDFUNCTION blend = {
         0 };
            blend.BlendOp = AC_SRC_OVER;
            blend.BlendFlags = 0;
            blend.AlphaFormat = AC_SRC_ALPHA;
            blend.SourceConstantAlpha = 128; // 透明度（0-255，255为完全不透明）
    
            RECT rcClient;
            GetClientRect(hWnd, &rcClient);
            FillRect(hdcMem, &rcClient, (HBRUSH)(COLOR_WINDOW + 1));
    
            // 使用UpdateLayeredWindow函数设置窗口为透明窗口
            POINT ptDst = {
         0, 0 };
            SIZE sizeWnd = {
         width, height };
            POINT ptSrc = {
         0, 0 };
            UpdateLayeredWindow(hWnd, hdc, NULL, &sizeWnd, hdcMem, &ptSrc, 0, &blend, ULW_ALPHA);
    
            // 释放资源
            DeleteDC(hdcMem);
            DeleteObject(hBitmap);
            ReleaseDC(hWnd, hdc);
        }
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hWnd, msg, wParam, lParam);
        }
        return 0;
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
    {
        
        const char* CLASS_NAME = "MyClass";
    
        WNDCLASS wc = {
         0 };
        wc.lpfnWndProc = WndProc;
        wc.hInstance = hInstance;
        wc.lpszClassName = CLASS_NAME;
        RegisterClass(&wc);
    
        HWND hWnd = CreateWindowEx(WS_EX_LAYERED, CLASS_NAME, "Transparent Window", WS_OVERLAPPEDWINDOW,
            CW_USEDEFAULT, CW_USEDEFAULT, 400, 300, NULL, NULL, hInstance, NULL);
    
        ShowWindow(hWnd, nCmdShow);
    
        MSG msg;
        while (GetMessage(&msg, NULL, 0, 0))
        {
        
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    
        return 0;
    }

## 二、半透明窗口实现 ##

### 1. 窗口透明绘图不透明 ###

窗口透明，绘图不透明的实现：

#include <windows.h>
    
    // 窗口类名称
    #define CLASS_NAME "MyWindowClass"
    
    // 窗口标题
    #define WINDOW_TITLE "Transparent Window"
    
    // 窗口大小
    #define WINDOW_WIDTH 640
    #define WINDOW_HEIGHT 480
    
    // GDI 绘图颜色
    #define DRAW_COLOR RGB(0, 0, 255)
    
    // 窗口透明色
    #define TRANSPARENT_COLOR RGB(0, 0, 0)
    
    // 窗口过程函数
    LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
    {
        
        switch (msg)
        {
        
        case WM_PAINT:
        {
        
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);
    
            // 使用透明色创建一个画刷
            HBRUSH hBrush = CreateSolidBrush(TRANSPARENT_COLOR);
    
            // 用画刷填充背景
            RECT rect;
            GetClientRect(hwnd, &rect);
            FillRect(hdc, &rect, hBrush);
    
            // 绘制一个不透明的矩形
            HBRUSH hDrawBrush = CreateSolidBrush(DRAW_COLOR);
            RECT drawRect = {
         50, 50, 200, 200 };
            FillRect(hdc, &drawRect, hDrawBrush);
    
            // 释放资源
            DeleteObject(hBrush);
            DeleteObject(hDrawBrush);
    
            EndPaint(hwnd, &ps);
            break;
        }
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
        }
    
        return 0;
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
    {
        
        // 注册窗口类
        WNDCLASS wc = {
         0 };
        wc.lpfnWndProc = WndProc;
        wc.hInstance = hInstance;
        wc.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
        wc.lpszClassName = CLASS_NAME;
        RegisterClass(&wc);
    
        // 创建窗口
        HWND hwnd = CreateWindowEx(WS_EX_LAYERED | WS_EX_TRANSPARENT | WS_EX_TOOLWINDOW,
            CLASS_NAME, WINDOW_TITLE,
            WS_POPUP | WS_VISIBLE,
            0, 0, WINDOW_WIDTH, WINDOW_HEIGHT,
            NULL, NULL, hInstance, NULL);
    
        // 设置透明色
        SetLayeredWindowAttributes(hwnd, TRANSPARENT_COLOR, 0, LWA_COLORKEY);
    
        // 消息循环
        MSG msg;
        while (GetMessage(&msg, NULL, 0, 0))
        {
        
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    
        return (int)msg.wParam;
    }

### 2. 窗口半透明绘图不透明 ###

#include <windows.h>
    
    // 窗口类名称
    #define CLASS_NAME L"MyWindowClass"
    
    // 窗口标题
    #define WINDOW_TITLE L"Transparent Window"
    
    // 窗口大小
    #define WINDOW_WIDTH 640
    #define WINDOW_HEIGHT 480
    
    // 窗口透明度
    #define WINDOW_ALPHA 200
    
    // 窗口过程函数
    LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
    {
        
        switch (msg)
        {
        
        case WM_DESTROY:
        {
        
            PostQuitMessage(0);
            break;
        }
        case WM_LBUTTONDBLCLK:
        {
        
            // 鼠标双击时关闭窗口
            DestroyWindow(hwnd);
            break;
        }
        case WM_LBUTTONDOWN:
        {
        
            // 鼠标左键按下时开始拖动窗口
            SendMessage(hwnd, WM_SYSCOMMAND, SC_MOVE | HTCAPTION, 0);
            break;
        }
        case WM_PAINT:
        {
        
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);
    
            // 绘制一个不透明的矩形
            HBRUSH hDrawBrush = CreateSolidBrush(RGB(0, 0, 255));
            RECT drawRect = {
         50, 50, 200, 200 };
            FillRect(hdc, &drawRect, hDrawBrush);
    
            // 释放资源
            DeleteObject(hDrawBrush);
    
            EndPaint(hwnd, &ps);
            break;
        }
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
        }
    
        return 0;
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
    {
        
        // 注册窗口类
        WNDCLASS wc = {
         0 };
        wc.lpfnWndProc = WndProc;
        wc.hInstance = hInstance;
        wc.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
        wc.lpszClassName = CLASS_NAME;
        wc.style = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;
        RegisterClass(&wc);
    
        // 创建窗口
        HWND hwnd = CreateWindowEx(WS_EX_LAYERED,
            CLASS_NAME, WINDOW_TITLE,
            WS_POPUP | WS_VISIBLE | WS_SYSMENU,
            0, 0, WINDOW_WIDTH, WINDOW_HEIGHT,
            NULL, NULL, hInstance, NULL);
    
        // 设置窗口透明度
        SetLayeredWindowAttributes(hwnd, 0, WINDOW_ALPHA, LWA_ALPHA);
    
        // 消息循环
        MSG msg;
        while (GetMessage(&msg, NULL, 0, 0))
        {
        
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    
        return 0;
    }

--------------------

参考资料：  
[各种常用的 Win32Api 汇总][Win32Api]  
[Win32窗口和Qt窗口部分透明实现][Win32_Qt]  
[Win32 使用 SetLayeredWindowAttributes 制作透明窗体][Win32 _ SetLayeredWindowAttributes]  
[使Win32窗口透明的几种方法][Win32]  
[windows api实现窗口透明整理][windows api]  
[win32去除窗体边框标题栏非客户区，保留阴影][win32]  
[\[Win32SDK基本\] 窗口详解（超详细）][Win32SDK_]  
[（详解入门）Windows（Win32） 应用程序的 简单窗口创建以及关键函数详细解释( 一 )][Windows_Win32_ _ _ _]  
[Win32绘图总结篇][Win32 1]

[Win32Api]: https://blog.csdn.net/weixin_42100963/article/details/107242265?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522168353111816800180634166%2522%252C%2522scm%2522%253A%252220140713.130102334..%2522%257D&request_id=168353111816800180634166&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~sobaiduend~default-2-107242265-null-null.142%5Ev86%5Einsert_down28,239%5Ev2%5Einsert_chatgpt&utm_term=win32&spm=1018.2226.3001.4187
[Win32_Qt]: https://blog.csdn.net/youyicc/article/details/124807387
[Win32 _ SetLayeredWindowAttributes]: https://bbs.huaweicloud.com/blogs/383902
[Win32]: https://www.bilibili.com/read/cv18607214/
[windows api]: https://blog.csdn.net/zhuiyuanqingya/article/details/80844258
[win32]: https://blog.csdn.net/qq_38701780/article/details/96560832?app_version=5.15.2&code=app_1562916241&csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%2296560832%22%2C%22source%22%3A%22hfy1237%22%7D&uLinkId=usr1mkqgl919blen&utm_source=app
[Win32SDK_]: https://blog.csdn.net/zuishikonghuan/article/details/46378475?app_version=5.15.2&code=app_1562916241&csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%2246378475%22%2C%22source%22%3A%22hfy1237%22%7D&uLinkId=usr1mkqgl919blen&utm_source=app
[Windows_Win32_ _ _ _]: https://blog.csdn.net/qq_45021180/article/details/97681459?app_version=5.15.2&code=app_1562916241&csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%2297681459%22%2C%22source%22%3A%22hfy1237%22%7D&uLinkId=usr1mkqgl919blen&utm_source=app
[Win32 1]: https://blog.csdn.net/qq_45021180/article/details/99612192?app_version=5.15.2&code=app_1562916241&csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%2299612192%22%2C%22source%22%3A%22hfy1237%22%7D&uLinkId=usr1mkqgl919blen&utm_source=app