一个Win32写的画图板程序

#include "windows.h"


HINSTANCE    hinst=NULL;
HWND        btn_close,btn_line,btn_rect,btn_ell,btn_cpen,btn_cbrush,btn_label;
HDC            hDC,hDC_lable;
RECT        drawrect,wndrect;
RECT        prect,brect;
HBRUSH        hbrush;
HPEN        hpen;
COLORREF    colpen,colbrush;
int            x,y;
HPEN hpen_temp;
HBRUSH hbrush_temp;

void CloseProc(HWND hwnd)
{
    DeleteObject(hbrush);
    DeleteObject(hpen);
    ReleaseDC(hwnd,hDC);
    UnregisterClass("Zapata",hinst);
    PostQuitMessage(0);    
}

void Paint(HWND hwnd)
{
    RECT wndrect;

    GetClientRect(hwnd,&wndrect);

    drawrect.bottom = wndrect.bottom - 10;
    drawrect.left    = wndrect.left + 120;
    drawrect.right    = wndrect.right - 10;
    drawrect.top    = wndrect.top + 10;

    FrameRect(hDC,&drawrect,CreateSolidBrush(0xff0000));

    prect.left = wndrect.left + 85;
    prect.top = wndrect.top + 110;
    prect.right = prect.left + 25;
    prect.bottom = prect.top + 25;

    brect.left = wndrect.left + 85;
    brect.top = wndrect.top + 140;
    brect.right = brect.left + 25;
    brect.bottom = brect.top + 25;

    hbrush    = CreateSolidBrush(colbrush);
    hpen    = CreatePen(PS_SOLID,1,colpen);

    SelectObject(hDC,hbrush);
    SelectObject(hDC,hpen);

    FillRect(hDC,&prect,CreateSolidBrush(colpen));
    FrameRect(hDC,&prect,CreateSolidBrush(0x000000));
    FillRect(hDC,&brect,CreateSolidBrush(colbrush));
    FrameRect(hDC,&brect,CreateSolidBrush(0x000000));
}

void cColor(HWND hwnd, int opt)
{
CHOOSECOLOR ccolor;
COLORREF    chos_color=0x000000;
COLORREF    chosed1[16]={0x0000ff,0x0000ff,0x0000ff,0x0000ff,
                        0x000000,0x000000,0x000000,0x000000,
                        0x000000,0x000000,0x000000,0x000000,
                        0xff0000,0xff0000,0xff0000,0xff0000};


    ZeroMemory(&ccolor,sizeof(CHOOSECOLOR));

    ccolor.lStructSize = sizeof(CHOOSECOLOR);
    ccolor.hwndOwner = hwnd;
    ccolor.rgbResult = chos_color;
    ccolor.lpCustColors = chosed1;
    ccolor.Flags = CC_RGBINIT|CC_FULLOPEN;
    ChooseColor(&ccolor);
    
    if(opt==1) colpen = ccolor.rgbResult;
    if(opt==2) colbrush = ccolor.rgbResult;
    Paint(hwnd);
}

int CheckBState(HWND hwnd)
{
    char txt[]="Choose Line, Rectangle or Ellipse!";

    if(SendMessage(btn_line,BM_GETCHECK,0,0)==1) return 1;
    if(SendMessage(btn_rect,BM_GETCHECK,0,0)==1) return 2;
    if(SendMessage(btn_ell,BM_GETCHECK,0,0)==1) return 3; 
    return 0;

}

void ObjectCreation(HWND hwnd)
{
    //GetClientRect(hwnd,&wndrect);    
    btn_line = CreateWindow("BUTTON","Line",WS_CHILD|WS_VISIBLE|BS_PUSHLIKE|BS_AUTORADIOBUTTON,wndrect.left+10,wndrect.top+10,100,25,hwnd,0,hinst,NULL);            
    btn_rect = CreateWindow("BUTTON","Rectangles",WS_CHILD|WS_VISIBLE|BS_PUSHLIKE|BS_AUTORADIOBUTTON,wndrect.left+10,wndrect.top+40,100,25,hwnd,0,hinst,NULL);            
    btn_ell = CreateWindow("BUTTON","Ellipses",WS_CHILD|WS_VISIBLE|BS_PUSHLIKE|BS_AUTORADIOBUTTON,wndrect.left+10,wndrect.top+70,100,25,hwnd,0,hinst,NULL);            
    btn_cpen = CreateWindow("BUTTON","Pen",WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,wndrect.left+10,wndrect.top+110,70,25,hwnd,0,hinst,NULL);
    btn_cbrush = CreateWindow("BUTTON","Brush",WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,wndrect.left+10,wndrect.top+140,70,25,hwnd,0,hinst,NULL);
    btn_label = CreateWindow("STATIC","",WS_CHILD|WS_VISIBLE|SS_BLACKFRAME,wndrect.left+10,wndrect.top+220,100,250,hwnd,0,hinst,NULL);

    btn_close = CreateWindow("BUTTON","Close",WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,wndrect.left+10,wndrect.top+180,100,25,hwnd,0,hinst,NULL);
}

void MoveMouse(HWND hwnd,int x,int y,int x1,int y1)
{
    static int a,b;
    static int i=0;
    if (i==0)
    {
        a=x;
        b=y;
        i++;
    }

    if(CheckBState(hwnd)==1)
    {
        LineTo(hDC,x,y);
        MoveToEx(hDC,x,y,NULL);
    }
    else if(CheckBState(hwnd)==2)
    {
        ////if(x1-a>1 && y1-b>1)
        //hpen_temp= CreatePen (PS_DOT, 1, (COLORREF)GetSysColor(COLOR_3DFACE)) ;
        //SelectObject(hDC,hpen_temp);
        ////Rectangle(hDC,x,y,a,b);
        //hpen_temp= CreatePen (PS_SOLID, 1, RGB(0,0,0)) ;
        //SelectObject(hDC,hpen_temp);
        //Rectangle(hDC,x,y,x1,y1);
        //a=x1;
        //b=y1;

        hbrush_temp= CreateSolidBrush ((COLORREF)GetSysColor(COLOR_3DFACE)) ;
        SelectObject(hDC,hbrush_temp);
        Rectangle(hDC,x,y,a,b);
        hpen_temp= CreatePen (PS_SOLID, 1, (COLORREF)GetSysColor(COLOR_3DFACE)) ;
        SelectObject(hDC,hpen_temp);
        Rectangle(hDC,x,y,a,b);//很重要的一点就是防止矩形往回拉的时候容易产生遗留图形.

        hpen_temp= CreatePen (PS_SOLID, 1, RGB(0,0,0)) ;
        SelectObject(hDC,hpen_temp);
        Rectangle(hDC,x,y,x1,y1);
        a=x1;
        b=y1;
    }
}

void DrawPrimitive(HWND hwnd,int x,int y,int x1,int y1)
{
    if(CheckBState(hwnd)==2)
    {
        Rectangle(hDC,x,y,x1,y1);
        return;
    }

    if(CheckBState(hwnd)==3)
    {
        Ellipse(hDC,x,y,x1,y1);
        return;
    }
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
    static int i=0;
    switch(msg)
    {
        case WM_DESTROY:
            CloseProc(hwnd);
            break;

        case WM_CREATE:
            ObjectCreation(hwnd);    
            break;

        case WM_SIZING:
            Paint(hwnd);
            break;

        case WM_ACTIVATE:
            Paint(hwnd);
            break;

        case WM_COMMAND:
            if(btn_close==(HWND)lParam) CloseProc(hwnd);
            if(btn_cpen==(HWND)lParam) cColor(hwnd,1);
            if(btn_cbrush==(HWND)lParam) cColor(hwnd,2);
            break;

        case WM_LBUTTONDOWN:
            x = LOWORD(lParam);
            y = HIWORD(lParam);
            if(x>drawrect.left & x<drawrect.right & y>drawrect.top & y<drawrect.bottom)
                MoveToEx(hDC,x,y,NULL);
            break;

        case WM_MOUSEMOVE:
            i++;
            hDC_lable = GetDC (btn_label) ;//使用GDI函数,显示在Label控件上
            TextOut(hDC_lable, 0+0.1*i,0-0.001*i, TEXT("nihao"), lstrlen(TEXT("nihao")));
            ReleaseDC (btn_label, hDC_lable) ;

            if(LOWORD(lParam)>drawrect.left & LOWORD(lParam)<drawrect.right & HIWORD(lParam)>drawrect.top & HIWORD(lParam)<drawrect.bottom)
                switch(wParam)
                {
                    case MK_LBUTTON:                    
                        MoveMouse(hwnd,x,y,LOWORD(lParam),HIWORD(lParam));
                        break;
                }

            break;

        //case WM_PAINT:

        //    break;

        case WM_LBUTTONUP:
            if(CheckBState(hwnd))
                if(LOWORD(lParam)>drawrect.left & LOWORD(lParam)<drawrect.right & HIWORD(lParam)>drawrect.top & HIWORD(lParam)<drawrect.bottom)
                    DrawPrimitive(hwnd,x,y,LOWORD(lParam),HIWORD(lParam));
            break;

        default:
            return DefWindowProc(hwnd,msg,wParam,lParam);
    }


    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrev,LPSTR cmdline,int CmdShow)
{
HWND        hwnd;
WNDCLASS    wc;
MSG            msg;

    hinst = hInstance;

    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL,IDC_ARROW);
    wc.hIcon = LoadIcon(NULL,IDI_APPLICATION);
    wc.lpfnWndProc = (WNDPROC) WndProc;
    wc.lpszClassName = "Zapata";
    wc.lpszMenuName = NULL;
    wc.style = CS_HREDRAW | CS_VREDRAW;

    RegisterClass(&wc);

    hwnd = CreateWindow("Zapata","Simple Drawing using Win32 API",WS_OVERLAPPEDWINDOW|DS_3DLOOK,CW_USEDEFAULT,0,CW_USEDEFAULT,0,0,0,hInstance,0);

    ShowWindow(hwnd,SW_SHOW);
    UpdateWindow(hwnd);

    hDC = GetDC(hwnd);
    colpen   = 0x000000;
    colbrush = 0xffffff;
    Paint(hwnd);

    while(GetMessage(&msg,0,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;
}