自己在学习WINDOWS程序编程过程中的入门画图程序

//----------------------------------------------------------------------- // // Name: HelloWorld4 example project // // Author: Mat Buckland 2002 // // Desc: Code to demonstrate basic keyboard handling // // NOTE: Don't forget to include the library winmm.lib in your project // settings. //------------------------------------------------------------------------ #include <windows.h> #include <time.h> #include <math.h> #include <stdlib.h> #include "defines.h" #include "resource.h" //--------------------------------- Globals ------------------------------ // //------------------------------------------------------------------------ char* g_szApplicationName = "HelloWorld"; char* g_szWindowClassName = "MyWindowClass"; //准备从每边画出几根线 static int iNumLinesPerSide=NUM_LINES; //多边形的顶点个数 static int iNumVerts=NUM_VERTS; //主窗口句柄的全局备份 HWND g_hwnd =NULL; //--------------------------------- DialogProc --------------------------- // //------------------------------------------------------------------------ BOOL CALLBACK OptionsDialogProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam ) { //取出编辑控件(edit controls)的句柄 HWND hwndiNumLines=GetDlgItem(hwnd,IDC_EDIT1); HWND hwndiNumVerts=GetDlgItem(hwnd,IDC_EDIT2); switch(msg) { case WM_INITDIALOG: { //使用当前的线数和边数显示在编辑框里 string s=itos(iNumLinesPerSide); SetWindowText(hwndiNumLines,s.c_str()); s=itos(iNumVerts); SetWindowText(hwndiNumVerts,s.c_str()); return true; } break; case WM_COMMAND: { switch(LOWORD(wParam)) { case IDOK: { //为每一个edit box收集信息,然后相应地改变对应的参数 char buffer[5]; //线数 GetWindowText(hwndiNumLines,buffer,5); //转换成一个int iNumLinesPerSide=atoi(buffer); //多边形边数 GetWindowText(hwndiNumVerts,buffer,5); //转换成一个int iNumVerts=atoi(buffer); //把一客户消息给WindowProc,这样新图形得到了 //PostMessage(g_hwnd,UM_SPAWN_NEW,NULL,NULL); //撤消对话框 EndDialog(hwnd,0); return true; } break; } } break; }//结束switch语句 return false; } BOOL CALLBACK AboutDialogProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch(msg) { case WM_INITDIALOG: { return true; } break; case WM_COMMAND: { switch(LOWORD(wParam)) { case IDOK: { EndDialog(hwnd,0); return true; } break; } } break; }//结束switch语句 return false; } //---------------------------- WindowProc --------------------------------- // // This is the callback function which handles all the windows messages //------------------------------------------------------------------------- LRESULT CALLBACK WindowProc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) { //create some pens HPEN RedPen =CreatePen(PS_SOLID,1,RGB(255,0 ,0 )); HPEN BluePen =CreatePen(PS_SOLID,1,RGB(0 ,0 ,255)); HPEN GreenPen =CreatePen(PS_SOLID,1,RGB(0 ,255,0 )); HPEN PurplePen =CreatePen(PS_SOLID,1,RGB(255,0 ,255)); HPEN OldPen =NULL;//OldPen为初始画笔 //create some brush HBRUSH RedBrush =CreateHatchBrush(HS_DIAGCROSS,RGB(255,0,0)); HBRUSH GreenBrush =CreateHatchBrush(HS_DIAGCROSS,RGB(0,255,0)); HBRUSH OldBrush =NULL; //用来存放建立的多边形顶点 static POINT verts[NUM_VERTS]; //定义随机函数 //inline int RandInt(int x,int y) {return rand()%(y-x+1)+x;} //自定义的函数要放在头文件 static int cxClient,cyClient; //创建back buffeer static HDC hdcBackBuffer; static HBITMAP hBitmap; static HBITMAP hOldBitmap; static HINSTANCE hInstance; switch (msg) { //A WM_CREATE msg is sent when your application window is first //created case WM_CREATE: { //取得hInstance hInstance=((LPCREATESTRUCT)lParam)->hInstance; PlaySound("window_open.wav", NULL, SND_FILENAME | SND_ASYNC); RECT rect; GetClientRect(hwnd,&rect); cxClient=rect.right; cyClient=rect.bottom; //激活一个随机数发生器 srand((unsigned) time(NULL)); //随机创建一些顶点 for(int v=0;v<iNumVerts;v++) { verts[v].x=RandInt(0,cxClient); verts[v].y=RandInt(0,cyClient); } //创建后备缓冲区 //先创建一个内存DC hdcBackBuffer=CreateCompatibleDC(NULL); //获取前置缓冲区的DC HDC hdc=GetDC(hwnd); hBitmap=CreateCompatibleBitmap(hdc, cxClient, cyClient); //将bitmap装入内存DC hOldBitmap=(HBITMAP)SelectObject(hdcBackBuffer,hBitmap); //释放DC ReleaseDC(hwnd,hdc); } break; case WM_KEYUP: { switch(wParam) { case VK_SPACE: { //为多边形随机地创建一些新的顶点 for(int v=0;v<iNumVerts;v++) { verts[v].x=RandInt(0,cxClient); verts[v].y=RandInt(0,cyClient); } //进行刷新,可以看到我们的新polygon InvalidateRect(hwnd,NULL,TRUE); UpdateWindow(hwnd); //UpdateWindow(hwnd)将WM_PAINT消息直接发给WindowProc,使窗口更新,创建新的多边形 } //如果按下了Escape键,就退出程序 // if(GetAsyncKeyState(VK_ESCAPE)) //此函数可以在任何地方来测试按键,不用麻烦消息循环 // PostQuitMessage(0); break; case VK_ESCAPE: { //如果按下了Escape键,就退出程序 PostQuitMessage(0); } break; } } case WM_PAINT: { //***********************************************************// //画图形 for(int v=0;v<iNumVerts;v++) { verts[v].x=RandInt(0,cxClient); verts[v].y=RandInt(0,cyClient); } PAINTSTRUCT ps; BeginPaint(hwnd, &ps); //用白色填充backbuffer BitBlt(hdcBackBuffer, 0, 0, cxClient, cyClient, NULL, NULL, NULL, WHITENESS); //**this is where we do any drawing to the screen** //draw q point at (200,200) SetPixel(hdcBackBuffer,200,200,RGB(255,0,0)); //将OldPen选为红笔,作为初始画笔 OldPen=(HPEN)SelectObject(hdcBackBuffer,RedPen); //将OldBrush选为红画刷,作为初始画刷 OldBrush=(HBRUSH)SelectObject(hdcBackBuffer,RedBrush); //select a brush SelectObject(hdcBackBuffer,RedBrush); //select a pen SelectObject(hdcBackBuffer,BluePen); //draw an ellipse at (200,200) Ellipse(hdcBackBuffer,300,300,500,500); //根据窗口尺寸计算所画各线的步长(即间距) int yStep=cyClient/iNumLinesPerSide; int xStep=cxClient/iNumLinesPerSide; //下面是画线的代码 for(int mult=1;mult<iNumLinesPerSide;++mult) { //select a pen SelectObject(hdcBackBuffer,RedPen); MoveToEx(hdcBackBuffer,xStep*mult,0,0); LineTo(hdcBackBuffer,0,cyClient-yStep*mult); //select a pen SelectObject(hdcBackBuffer,GreenPen); MoveToEx(hdcBackBuffer,xStep*mult,cyClient,0); LineTo(hdcBackBuffer,cxClient,cyClient-yStep*mult); //select a pen SelectObject(hdcBackBuffer,PurplePen); MoveToEx(hdcBackBuffer,xStep*mult,0,0); LineTo(hdcBackBuffer,cxClient,yStep*mult); //select a pen SelectObject(hdcBackBuffer,BluePen); MoveToEx(hdcBackBuffer,xStep*mult,cyClient,0); LineTo(hdcBackBuffer,0,yStep*mult); } //select a pen & a brush and draw a polygon SelectObject(hdcBackBuffer,PurplePen); SelectObject(hdcBackBuffer,GreenB