win32 API編程之GDI繪圖

一、GDI簡介

二、獲取DC的3種方法

三、繪圖函數

四、雙緩沖繪圖技術

五、繪制位圖

 

 

 

一、GDI簡介

1）什么是設備上下文

2）設備上下文類型

3）常見的GDI對象

4）windows坐標系

5）GDI繪圖步驟

二、獲取DC的3種方法

1）獲取DC的3種方法

2）PAINTSTRUCT結構

3）BeginPaint函數

4）EndPaint函數

5）GetDC函數

6）GetWindowDC函數

7）三種方式的區別

8）代碼實例

#include<windows.h> 


//自定義的窗口過程
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，它能將無效區域變成有效（如果存在無效區域，系統會一直發送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獲取客戶區DC，它並不能將無效區域變成有效,所以WM_PAINT一直發送，文字一直閃爍
        /*
        HDC  hdc = GetDC(hWnd);
        TextOut(hdc, 0, 0, L"你好啊！", lstrlen(L"你好啊！"));
        ReleaseDC(hWnd, hdc);
        //return 0; //去掉之后交給默認DefWindowProc處理WM_PAINT消息，會調用BeginPaint，EndPaint
        */ 

    }
    break;

    case WM_NCPAINT:
    {
        //3.獲取整個窗口的DC，包括標題欄，工具條等
        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);//釋放掉DC
        return  true;


    }break;

    }

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


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

    //1.注冊窗口類
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光標
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖標
                                                //wnd.lpfnWndProc = DefWindowProc;//默認窗口過程函數，用於處理消息
    wnd.lpfnWndProc = MyWindowProc;//自定義的窗口過程函數
    wnd.lpszClassName = L"MrHuang";//窗口類名
    wnd.lpszMenuName = NULL;//菜單資源名稱
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口類、樣式
    wnd.hInstance = hInstance;//實例句柄
    RegisterClass(&wnd);

    //創建窗口(返回之前發送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一個窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //顯示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(發送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循環（收到WM_QUIT消息退出）
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻譯消息
        DispatchMessage(&msg);//分發消息到窗口過程
    }
}

三、繪圖函數

1）創建畫筆

2）選擇一個對象到數據上下文

3）畫直線

                                            

4）畫矩形

5）創建畫刷

6）DeleteObject函數

7）GetStockObject函數

8）畫橢圓

9）畫餅圖

10）寫入字符串

11）SetBkColor函數

12）SetBkMode函數

13）DrawText函數

14）SetTextAlign函數

15）代碼實例

①繪制直線、矩形、橢圓、餅圖

#include<windows.h> 


//自定義的窗口過程
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;
        //獲取設備上下文句柄
        HDC   hdc = BeginPaint(hWnd, &ps);
 
        //創建畫筆
        HPEN  hPen = CreatePen(PS_DASHDOT, 1, RGB(255, 0, 0));
        //將筆選入到設備上下文(使用這支筆)
        SelectObject(hdc, hPen);

        //1.畫直線(兩個點)
        MoveToEx(hdc, 100, 100, NULL);
        LineTo(hdc, 200, 100);

        //創建畫刷
        HBRUSH hBsh = CreateSolidBrush(RGB(0, 255, 0));
        //將畫刷選入到設備上下文(使用這支畫刷)
        SelectObject(hdc, hBsh);
         
        //2.畫矩形(正方形)
        Rectangle(hdc, 200, 200, 400, 400);


        //獲取透明畫刷
        HGDIOBJ hBsh2  =GetStockObject(NULL_BRUSH);
        SelectObject(hdc, hBsh2);
        Rectangle(hdc,  100, 100, 200, 150);

        //3.畫橢圓（圓形）
        Ellipse(hdc, 200, 200, 400, 400);
        Ellipse(hdc, 100, 100, 200, 150);


        //4.畫餅圖 
/*            
        //餅圖產生的步驟分解
        Ellipse(hdc, 500, 100, 800, 400); 
         //從圓心到第一個點的連線
         MoveToEx(hdc, 650, 250, NULL);
         LineTo(hdc,1000, 300);  
         //從圓心到第二個點的連線
         MoveToEx(hdc, 650, 250, NULL);
         LineTo(hdc, 400, 400);
 */        
         Pie(hdc, 500, 100, 800, 400, 1000, 300,400, 400);


        //刪除GDI對象
        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.注冊窗口類
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光標
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖標
                                                //wnd.lpfnWndProc = DefWindowProc;//默認窗口過程函數，用於處理消息
    wnd.lpfnWndProc = MyWindowProc;//自定義的窗口過程函數
    wnd.lpszClassName = L"MrHuang";//窗口類名
    wnd.lpszMenuName = NULL;//菜單資源名稱
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口類、樣式
    wnd.hInstance = hInstance;//實例句柄
    RegisterClass(&wnd);

    //創建窗口(返回之前發送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一個窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 1000, 700, NULL, NULL, hInstance, NULL);

    //顯示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(發送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循環（收到WM_QUIT消息退出）
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻譯消息
        DispatchMessage(&msg);//分發消息到窗口過程
    }
}

②寫入字符串

#include<windows.h> 


//自定義的窗口過程
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;
        //獲取設備上下文句柄
        HDC   hdc = BeginPaint(hWnd, &ps);

        //改變文本的背景色
        SetBkColor(hdc, RGB(255, 0, 0));
        //設置文本背景模式 
        SetBkMode(hdc, TRANSPARENT);//透明

        //設置文本的顏色
        SetTextColor(hdc, RGB(255, 0, 0));


        //設置文本的參考點
        SetTextAlign(hdc, TA_TOP);

        //1.界面上畫文本
        TextOut(hdc,250, 200, L"你好啊，這是畫的文本！", lstrlen(L"你好啊，這是畫的文本！"));

        //2.在矩形范圍中畫文本
        RECT  r = {250,400,300,500};
        Rectangle(hdc, r.left, r.top, r.right, r.bottom);
        DrawText(hdc, L"你好啊，這是畫的文本！", lstrlen(L"你好啊，這是畫的文本！")
            , &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.注冊窗口類
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光標
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖標
                                                //wnd.lpfnWndProc = DefWindowProc;//默認窗口過程函數，用於處理消息
    wnd.lpfnWndProc = MyWindowProc;//自定義的窗口過程函數
    wnd.lpszClassName = L"MrHuang";//窗口類名
    wnd.lpszMenuName = NULL;//菜單資源名稱
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口類、樣式
    wnd.hInstance = hInstance;//實例句柄
    RegisterClass(&wnd);

    //創建窗口(返回之前發送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一個窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 1000, 700, NULL, NULL, hInstance, NULL);

    //顯示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(發送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循環（收到WM_QUIT消息退出）
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻譯消息
        DispatchMessage(&msg);//分發消息到窗口過程
    }
}

四、雙緩沖繪制技術

1）什么是雙緩沖繪制技術

2）步驟

3）CreateCompatiableDC函數

4）CreateCompatiableBitmap函數

5）BitBlt函數

6）StretchBlt函數

7）代碼實例

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


//自定義的窗口過程
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.創建兼容內存DC,此時它的大小時1X1，很小，不能繪制
        HDC  hMemDC=CreateCompatibleDC(hdc);

        //2.創建兼容位圖，提供繪畫區域
        HBITMAP hMemBmp = CreateCompatibleBitmap(hdc, 100, 100);

        //3.把兼容位圖選到兼容內存DC中,此刻DC的大小與位圖一致，可以繪制
        SelectObject(hMemDC, hMemBmp);

        //4.在兼容內存DC上進行繪圖操作
        SetTextColor(hMemDC, RGB(255, 0, 0));
        TextOut(hMemDC, 0, 0, L"雙緩沖技術繪制！", lstrlen(L"雙緩沖技術繪制！")); 
        Rectangle(hMemDC, 30, 30, 80, 80);

        //5.把內存DC中的圖像一次性畫到窗口DC上
         //不拉伸
         BitBlt(hdc, 0, 0, 100, 100, hMemDC, 0, 0, SRCCOPY);
        
         //拉伸(目標矩形大於源矩形)
         StretchBlt(hdc, 0, 0, 400, 400, hMemDC, 0, 0,100,100, SRCCOPY);
         //壓縮(目標矩形小於源矩形)
         StretchBlt(hdc, 0, 0, 50, 50, hMemDC, 0, 0, 100, 100, SRCCOPY);


         //釋放資源
         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.注冊窗口類
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光標
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖標
                                                //wnd.lpfnWndProc = DefWindowProc;//默認窗口過程函數，用於處理消息
    wnd.lpfnWndProc = MyWindowProc;//自定義的窗口過程函數
    wnd.lpszClassName = L"MrHuang";//窗口類名
    wnd.lpszMenuName = NULL;//菜單資源名稱
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口類、樣式
    wnd.hInstance = hInstance;//實例句柄
    RegisterClass(&wnd);

    //創建窗口(返回之前發送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一個窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //顯示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(發送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循環（收到WM_QUIT消息退出）
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻譯消息
        DispatchMessage(&msg);//分發消息到窗口過程
    }
}

五、繪制位圖

1）什么是位圖

2）位圖繪制的步驟

3）LoadImage函數

4）SetStrechBltMode函數

5）代碼實例

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


//自定義的窗口過程
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.創建內存兼容DC（1px  X  1px）
        HDC  hMemDC = CreateCompatibleDC(hdc);

        //2.加載位圖資源
        HBITMAP hBmp= (HBITMAP)LoadImage(NULL, L"bg.bmp", IMAGE_BITMAP, 800, 800, LR_LOADFROMFILE);

        //3.把位圖選入到兼容內存DC
        SelectObject(hMemDC, hBmp);

        //添加水印
        TextOut(hMemDC, 100, 100, L"亂塗亂畫", lstrlen(L"亂塗亂畫"));
         
        //設置圖像拉伸模式
        //SetStretchBltMode(hdc, COLORONCOLOR);//刪除多余像素
        SetStretchBltMode(hdc, HALFTONE); 

        //4.將兼容DC中的圖像一次性拷貝到窗口DC上
         //BitBlt(hdc, 0, 0, 800, 800, hMemDC, 0, 0, SRCCOPY);
        //完整顯示
         StretchBlt(hdc, 0, 0, 400, 400, hMemDC, 0, 0, 800,800,SRCCOPY);

        //5.釋放DC與位圖資源
        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.注冊窗口類
    WNDCLASS  wnd;
    wnd.cbClsExtra = 0;
    wnd.cbWndExtra = 0;
    wnd.hbrBackground = (HBRUSH)(GetStockObject(GRAY_BRUSH));//背景色
    wnd.hCursor = LoadCursor(NULL, IDC_ARROW);//光標
    wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖標
                                                //wnd.lpfnWndProc = DefWindowProc;//默認窗口過程函數，用於處理消息
    wnd.lpfnWndProc = MyWindowProc;//自定義的窗口過程函數
    wnd.lpszClassName = L"MrHuang";//窗口類名
    wnd.lpszMenuName = NULL;//菜單資源名稱
    wnd.style = CS_HREDRAW | CS_DBLCLKS;//窗口類、樣式
    wnd.hInstance = hInstance;//實例句柄
    RegisterClass(&wnd);

    //創建窗口(返回之前發送WM_CREATE)
    HWND    hWnd = CreateWindow(L"MrHuang", L"第一個窗口程序",
        WS_OVERLAPPEDWINDOW, 100, 100, 400, 400, NULL, NULL, hInstance, NULL);

    //顯示窗口
    ShowWindow(hWnd, nShowCmd);
    //更新窗口(發送WM_PAINT)
    UpdateWindow(hWnd);

    //消息循環（收到WM_QUIT消息退出）
    MSG  msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);//翻譯消息
        DispatchMessage(&msg);//分發消息到窗口過程
    }
}