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win32 API编程之GDI绘图

作者:互联网

一、GDI简介

1)什么是设备上下文

2)设备上下文类型

3)常见的GDI对象

4)windows坐标系

5)GDI绘图步骤

二、获取DC的3种方法

1)获取DC的3种方法

2)PAINTSTRUCT结构

3)BeginPaint函数

4)EndPaint函数

5)GetDC函数

6)GetWindowDC函数

7)三种方式的区别

8)代码实例

#include<windows.h> 


//自定义的窗口过程
LRESULT  CALLBACK    MyWindowProc(HWND hWnd, UINT Msg,
    WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0    
        return 0;

    case WM_PAINT:
    { 
        //1.使用BeginPaint,它能将无效区域变成有效(如果存在无效区域,系统会一直发送WM_PAINT)
        /*PAINTSTRUCT  ps;
        HDC  hdc = BeginPaint(hWnd, &ps);
        TextOut(hdc, 0, 0, L"你好啊!", lstrlen(L"你好啊!"));
        EndPaint(hWnd, &ps);*/

        //2.使用GetDC获取客户区DC,它并不能将无效区域变成有效,所以WM_PAINT一直发送,文字一直闪烁
        /*
        HDC  hdc = GetDC(hWnd);
        TextOut(hdc, 0, 0, L"你好啊!", lstrlen(L"你好啊!"));
        ReleaseDC(hWnd, hdc);
        //return 0; //去掉之后交给默认DefWindowProc处理WM_PAINT消息,会调用BeginPaint,EndPaint
        */ 

    }
    break;

    case WM_NCPAINT:
    {
        //3.获取整个窗口的DC,包括标题栏,工具条等
        HDC  hdc = GetWindowDC(hWnd);
        RECT  r = {0,0,400,20};
        HBRUSH  brh = CreateSolidBrush(RGB(255, 0, 0));
        FillRect(hdc, &r, brh);
        DeleteObject(brh);
        ReleaseDC(hWnd, hdc);//释放掉DC
        return  true;


    }break;

    }

    return DefWindowProc(hWnd, Msg, wParam, lParam);
}


int  WINAPI   WinMain(HINSTANCE  hInstance, HINSTANCE  hPrevInstance,
    LPSTR lpCmdLine, int  nShowCmd)
{

    //1.注册窗口类
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光标
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//图标
                                                //wnd.lpfnWndProc = DefWindowProc;//默认窗口过程函数,用于处理消息
    wnd.lpfnWndProc = MyWindowProc;//自定义的窗口过程函数
    wnd.lpszClassName = L"MrHuang";//窗口类名
    wnd.lpszMenuName = NULL;//菜单资源名称
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口类、样式
    wnd.hInstance = hInstance;//实例句柄
    RegisterClass(&wnd);

    //创建窗口(返回之前发送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一个窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //显示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(发送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循环(收到WM_QUIT消息退出)
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻译消息
        DispatchMessage(&msg);//分发消息到窗口过程
    }
}

三、绘图函数

1)创建画笔

2)选择一个对象到数据上下文

3)画直线

                                            

4)画矩形

5)创建画刷

6)DeleteObject函数

7)GetStockObject函数

8)画椭圆

9)画饼图

10)写入字符串

11)SetBkColor函数

12)SetBkMode函数

13)DrawText函数

14)SetTextAlign函数

15)代码实例

①绘制直线、矩形、椭圆、饼图

#include<windows.h> 


//自定义的窗口过程
LRESULT  CALLBACK    MyWindowProc(HWND hWnd, UINT Msg,
    WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0    
        return 0;

    case WM_PAINT: 
    {
        PAINTSTRUCT ps;
        //获取设备上下文句柄
        HDC   hdc = BeginPaint(hWnd, &ps);
 
        //创建画笔
        HPEN  hPen = CreatePen(PS_DASHDOT, 1, RGB(255, 0, 0));
        //将笔选入到设备上下文(使用这支笔)
        SelectObject(hdc, hPen);

        //1.画直线(两个点)
        MoveToEx(hdc, 100, 100, NULL);
        LineTo(hdc, 200, 100);

        //创建画刷
        HBRUSH hBsh = CreateSolidBrush(RGB(0, 255, 0));
        //将画刷选入到设备上下文(使用这支画刷)
        SelectObject(hdc, hBsh);
         
        //2.画矩形(正方形)
        Rectangle(hdc, 200, 200, 400, 400);


        //获取透明画刷
        HGDIOBJ hBsh2  =GetStockObject(NULL_BRUSH);
        SelectObject(hdc, hBsh2);
        Rectangle(hdc,  100, 100, 200, 150);

        //3.画椭圆(圆形)
        Ellipse(hdc, 200, 200, 400, 400);
        Ellipse(hdc, 100, 100, 200, 150);


        //4.画饼图 
/*            
        //饼图产生的步骤分解
        Ellipse(hdc, 500, 100, 800, 400); 
         //从圆心到第一个点的连线
         MoveToEx(hdc, 650, 250, NULL);
         LineTo(hdc,1000, 300);  
         //从圆心到第二个点的连线
         MoveToEx(hdc, 650, 250, NULL);
         LineTo(hdc, 400, 400);
 */        
         Pie(hdc, 500, 100, 800, 400, 1000, 300,400, 400);


        //删除GDI对象
        DeleteObject(hPen);
        DeleteObject(hBsh);

        EndPaint(hWnd, &ps);
    }
    break;

    }

    return DefWindowProc(hWnd, Msg, wParam, lParam);
}


int  WINAPI   WinMain(HINSTANCE  hInstance, HINSTANCE  hPrevInstance,
    LPSTR lpCmdLine, int  nShowCmd)
{

    //1.注册窗口类
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光标
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//图标
                                                //wnd.lpfnWndProc = DefWindowProc;//默认窗口过程函数,用于处理消息
    wnd.lpfnWndProc = MyWindowProc;//自定义的窗口过程函数
    wnd.lpszClassName = L"MrHuang";//窗口类名
    wnd.lpszMenuName = NULL;//菜单资源名称
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口类、样式
    wnd.hInstance = hInstance;//实例句柄
    RegisterClass(&wnd);

    //创建窗口(返回之前发送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一个窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 1000, 700, NULL, NULL, hInstance, NULL);

    //显示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(发送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循环(收到WM_QUIT消息退出)
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻译消息
        DispatchMessage(&msg);//分发消息到窗口过程
    }
}

②写入字符串

#include<windows.h> 


//自定义的窗口过程
LRESULT  CALLBACK    MyWindowProc(HWND hWnd, UINT Msg,
    WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0    
        return 0;

    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        //获取设备上下文句柄
        HDC   hdc = BeginPaint(hWnd, &ps);

        //改变文本的背景色
        SetBkColor(hdc, RGB(255, 0, 0));
        //设置文本背景模式 
        SetBkMode(hdc, TRANSPARENT);//透明

        //设置文本的颜色
        SetTextColor(hdc, RGB(255, 0, 0));


        //设置文本的参考点
        SetTextAlign(hdc, TA_TOP);

        //1.界面上画文本
        TextOut(hdc,250, 200, L"你好啊,这是画的文本!", lstrlen(L"你好啊,这是画的文本!"));

        //2.在矩形范围中画文本
        RECT  r = {250,400,300,500};
        Rectangle(hdc, r.left, r.top, r.right, r.bottom);
        DrawText(hdc, L"你好啊,这是画的文本!", lstrlen(L"你好啊,这是画的文本!")
            , &r,  DT_BOTTOM|DT_SINGLELINE);




        EndPaint(hWnd, &ps);
    }
    break;

    }

    return DefWindowProc(hWnd, Msg, wParam, lParam);
}


int  WINAPI   WinMain(HINSTANCE  hInstance, HINSTANCE  hPrevInstance,
    LPSTR lpCmdLine, int  nShowCmd)
{

    //1.注册窗口类
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光标
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//图标
                                                //wnd.lpfnWndProc = DefWindowProc;//默认窗口过程函数,用于处理消息
    wnd.lpfnWndProc = MyWindowProc;//自定义的窗口过程函数
    wnd.lpszClassName = L"MrHuang";//窗口类名
    wnd.lpszMenuName = NULL;//菜单资源名称
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口类、样式
    wnd.hInstance = hInstance;//实例句柄
    RegisterClass(&wnd);

    //创建窗口(返回之前发送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一个窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 1000, 700, NULL, NULL, hInstance, NULL);

    //显示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(发送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循环(收到WM_QUIT消息退出)
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻译消息
        DispatchMessage(&msg);//分发消息到窗口过程
    }
}

四、双缓冲绘制技术

1)什么是双缓冲绘制技术

2)步骤

3)CreateCompatiableDC函数

4)CreateCompatiableBitmap函数

5)BitBlt函数

6)StretchBlt函数

7)代码实例

#include<windows.h>
#include<CommCtrl.h> 


//自定义的窗口过程
LRESULT  CALLBACK    MyWindowProc(HWND hWnd, UINT Msg,
    WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0    
        return 0;

    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC   hdc = BeginPaint(hWnd, &ps);
 
         //1.创建兼容内存DC,此时它的大小时1X1,很小,不能绘制
        HDC  hMemDC=CreateCompatibleDC(hdc);

        //2.创建兼容位图,提供绘画区域
        HBITMAP hMemBmp = CreateCompatibleBitmap(hdc, 100, 100);

        //3.把兼容位图选到兼容内存DC中,此刻DC的大小与位图一致,可以绘制
        SelectObject(hMemDC, hMemBmp);

        //4.在兼容内存DC上进行绘图操作
        SetTextColor(hMemDC, RGB(255, 0, 0));
        TextOut(hMemDC, 0, 0, L"双缓冲技术绘制!", lstrlen(L"双缓冲技术绘制!")); 
        Rectangle(hMemDC, 30, 30, 80, 80);

        //5.把内存DC中的图像一次性画到窗口DC上
         //不拉伸
         BitBlt(hdc, 0, 0, 100, 100, hMemDC, 0, 0, SRCCOPY);
        
         //拉伸(目标矩形大于源矩形)
         StretchBlt(hdc, 0, 0, 400, 400, hMemDC, 0, 0,100,100, SRCCOPY);
         //压缩(目标矩形小于源矩形)
         StretchBlt(hdc, 0, 0, 50, 50, hMemDC, 0, 0, 100, 100, SRCCOPY);


         //释放资源
         DeleteDC(hMemDC);
         DeleteObject(hMemBmp);


        EndPaint(hWnd, &ps);
    }
    break;

    }

    return DefWindowProc(hWnd, Msg, wParam, lParam);
}


int  WINAPI   WinMain(HINSTANCE  hInstance, HINSTANCE  hPrevInstance,
    LPSTR lpCmdLine, int  nShowCmd)
{

    //1.注册窗口类
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光标
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//图标
                                                //wnd.lpfnWndProc = DefWindowProc;//默认窗口过程函数,用于处理消息
    wnd.lpfnWndProc = MyWindowProc;//自定义的窗口过程函数
    wnd.lpszClassName = L"MrHuang";//窗口类名
    wnd.lpszMenuName = NULL;//菜单资源名称
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口类、样式
    wnd.hInstance = hInstance;//实例句柄
    RegisterClass(&wnd);

    //创建窗口(返回之前发送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一个窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //显示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(发送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循环(收到WM_QUIT消息退出)
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻译消息
        DispatchMessage(&msg);//分发消息到窗口过程
    }
}

五、绘制位图

1)什么是位图

2)位图绘制的步骤

3)LoadImage函数

4)SetStrechBltMode函数

5)代码实例

#include<windows.h>
#include<CommCtrl.h> 


//自定义的窗口过程
LRESULT  CALLBACK    MyWindowProc(HWND hWnd, UINT Msg,
    WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);//可以使GetMessage返回0    
        return 0;

    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC   hdc = BeginPaint(hWnd, &ps);

        //1.创建内存兼容DC(1px  X  1px)
        HDC  hMemDC = CreateCompatibleDC(hdc);

        //2.加载位图资源
        HBITMAP hBmp= (HBITMAP)LoadImage(NULL, L"bg.bmp", IMAGE_BITMAP, 800, 800, LR_LOADFROMFILE);

        //3.把位图选入到兼容内存DC
        SelectObject(hMemDC, hBmp);

        //添加水印
        TextOut(hMemDC, 100, 100, L"乱涂乱画", lstrlen(L"乱涂乱画"));
         
        //设置图像拉伸模式
        //SetStretchBltMode(hdc, COLORONCOLOR);//删除多余像素
        SetStretchBltMode(hdc, HALFTONE); 

        //4.将兼容DC中的图像一次性拷贝到窗口DC上
         //BitBlt(hdc, 0, 0, 800, 800, hMemDC, 0, 0, SRCCOPY);
        //完整显示
         StretchBlt(hdc, 0, 0, 400, 400, hMemDC, 0, 0, 800,800,SRCCOPY);

        //5.释放DC与位图资源
        DeleteObject(hBmp);
        DeleteDC(hMemDC);
      
        EndPaint(hWnd, &ps);
    }
    break;

    }

    return DefWindowProc(hWnd, Msg, wParam, lParam);
}


int  WINAPI   WinMain(HINSTANCE  hInstance, HINSTANCE  hPrevInstance,
    LPSTR lpCmdLine, int  nShowCmd)
{

    //1.注册窗口类
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光标
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//图标
                                                //wnd.lpfnWndProc = DefWindowProc;//默认窗口过程函数,用于处理消息
    wnd.lpfnWndProc = MyWindowProc;//自定义的窗口过程函数
    wnd.lpszClassName = L"MrHuang";//窗口类名
    wnd.lpszMenuName = NULL;//菜单资源名称
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口类、样式
    wnd.hInstance = hInstance;//实例句柄
    RegisterClass(&wnd);

    //创建窗口(返回之前发送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一个窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //显示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(发送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循环(收到WM_QUIT消息退出)
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻译消息
        DispatchMessage(&msg);//分发消息到窗口过程
    }
}

 

标签:窗口,wnd,hWnd,WM,win32,API,hdc,GDI,NULL
来源: https://www.cnblogs.com/mango1997/p/14628463.html