绘图(直线，曲线)例子
画数学函数：
#include<windows.h>#include<math.h>#define NUM 1000#define TWOPI (2*3.14159)LRESULT CALLBACK WindowProc( HWND hwnd, // handle to window UINT uMsg, // message identifier WPARAM wParam, // first message parameter LPARAM lParam // second message parameter);int WINAPI WinMain( HINSTANCE hInstance, // handle to current instance HINSTANCE hPrevInstance, // handle to previous instance LPSTR lpCmdLine, // command line int nCmdShow // show state){static TCHAR szAppName[]=TEXT("leidemingzi");HWND hwnd;MSG msg;WNDCLASS wndclass; wndclass.cbClsExtra=0;wndclass.cbWndExtra=0;wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);wndclass.hCursor=LoadCursor(NULL,IDC_HELP);wndclass.hIcon=LoadIcon(NULL,IDI_EXCLAMATION);wndclass.hInstance=hInstance;wndclass.lpfnWndProc=WindowProc;wndclass.lpszClassName=szAppName;wndclass.lpszMenuName=NULL;wndclass.style=CS_HREDRAW|CS_VREDRAW;if(!RegisterClass(&wndclass)){MessageBox(NULL,TEXT("the program require windows NT"),szAppName,MB_YESNO);return 0;}hwnd=CreateWindow( szAppName, // registered class name TEXT("this is title"), // window name WS_OVERLAPPEDWINDOW, // window style CW_USEDEFAULT, // horizontal position of window CW_USEDEFAULT, // vertical position of window CW_USEDEFAULT, // window width CW_USEDEFAULT, // window height NULL, // handle to parent or owner window NULL, // menu handle or child identifier hInstance, // handle to application instance NULL // window-creation data);ShowWindow(hwnd,nCmdShow);UpdateWindow(hwnd);while(GetMessage(&msg,NULL,0,0)){TranslateMessage(&msg);DispatchMessage(&msg);}return msg.wParam;}LRESULT CALLBACK WindowProc( HWND hwnd, // handle to window UINT uMsg, // message identifier WPARAM wParam, // first message parameter LPARAM lParam // second message parameter){static int cxClient,cyClient;HDC hdc;int i;PAINTSTRUCT ps;POINT apt[NUM];switch(uMsg){case WM_SIZE:cxClient=LOWORD(lParam);cyClient=HIWORD(lParam);return 0;case WM_PAINT:hdc=BeginPaint(hwnd,&ps);MoveToEx(hdc,0,cyClient/2,NULL);LineTo(hdc,cxClient,cyClient/2);for(i=0;i<NUM;++i){apt[i].x=i*cxClient/NUM;apt[i].y=(int)(cyClient/2*(1-sin(TWOPI*i/NUM)));//数学不会太差都应该可以算出来}Polyline(hdc,apt,NUM);//PolyBezier(hdc,apt,NUM);//Rectangle(hdc,100,100,500,400); //画一个矩形//RoundRect(hdc,100,100,500,400,100,75);//画一个圆角矩形倒数第二个参数=(xright-xleft)/4 倒数第一参数=(buttom-top)/4//Ellipse(hdc,100,100,500,400);//画一个椭圆//Arc(hdc,100,100,500,400,300,200,400,360);//画椭圆曲线//Chord(hdc,100,100,500,400,300,200,400,360);//画弓形//Pie(hdc,100,100,500,400,300,200,400,360);//画扇形/*Rectangle(hdc,cxClient/8,cyClient/8,7*cxClient/8,7*cyClient/8);//下面这一段代码画的是什么呢？调试下吧MoveToEx(hdc,0,0,NULL);LineTo(hdc,cxClient,cyClient);MoveToEx(hdc,0,cyClient,NULL);LineTo(hdc,cxClient,0);Ellipse(hdc,cxClient/8,cyClient/8,7*cxClient/8,7*cyClient/8);RoundRect(hdc,cxClient/4,cyClient/4,3*cxClient/4,3*cyClient/4,cxClient/4,cyClient/4);*/EndPaint(hwnd,&ps);return 0;case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd,uMsg,wParam,lParam);}
其他 什么矩形，圆矩形...自己把注释去掉，自己调试吧。
下面是一个贝赛样曲线：
#include <windows.h> LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow){ static TCHAR szAppName[] = TEXT ("Bezier") ; HWND hwnd ; MSG msg ; WNDCLASS wndclass ; wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; wndclass.cbClsExtra = 0 ; wndclass.cbWndExtra = 0 ; wndclass.hInstance = hInstance ; wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ; wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ; wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ; wndclass.lpszMenuName = NULL ; wndclass.lpszClassName = szAppName ; if (!RegisterClass (&wndclass)) { MessageBox (NULL, TEXT ("Program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow (szAppName, TEXT ("Bezier Splines"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ; while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ;}void DrawBezier (HDC hdc, POINT apt[]){ PolyBezier (hdc, apt, 4) ; MoveToEx (hdc, apt[0].x, apt[0].y, NULL) ; LineTo (hdc, apt[1].x, apt[1].y) ; MoveToEx (hdc, apt[2].x, apt[2].y, NULL) ; LineTo (hdc, apt[3].x, apt[3].y) ;}LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){ static POINT apt[4] ; HDC hdc ; int cxClient, cyClient ; PAINTSTRUCT ps ; switch (message) { case WM_SIZE: cxClient = LOWORD (lParam) ; cyClient = HIWORD (lParam) ; apt[0].x = cxClient / 4 ; apt[0].y = cyClient / 2 ; apt[1].x = cxClient / 2 ; apt[1].y = cyClient / 4 ; apt[2].x = cxClient / 2 ; apt[2].y = 3 * cyClient / 4 ; apt[3].x = 3 * cxClient / 4 ; apt[3].y = cyClient / 2 ; return 0 ; case WM_LBUTTONDOWN: case WM_RBUTTONDOWN: case WM_MOUSEMOVE: if (wParam & MK_LBUTTON || wParam & MK_RBUTTON) { hdc = GetDC (hwnd) ; SelectObject (hdc, GetStockObject (WHITE_PEN)) ; DrawBezier (hdc, apt) ; if (wParam & MK_LBUTTON) { apt[1].x = LOWORD (lParam) ; apt[1].y = HIWORD (lParam) ; } if (wParam & MK_RBUTTON) { apt[2].x = LOWORD (lParam) ; apt[2].y = HIWORD (lParam) ; } SelectObject (hdc, GetStockObject (BLACK_PEN)) ; DrawBezier (hdc, apt) ; ReleaseDC (hwnd, hdc) ; } return 0 ; case WM_PAINT: InvalidateRect (hwnd, NULL, TRUE) ; hdc = BeginPaint (hwnd, &ps) ; DrawBezier (hdc, apt) ; EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY: PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ;}结果如下（鼠标左键右键可以控制弧度）
