这个怎么实现？

Question

上面代码错了#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define PI 3.1415926 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
  )
{
    HWND hwnd;
    MSG Msg;
    WNDCLASS wndclass;
    wndclass.cbClsExtra=0;
    wndclass.cbWndExtra=0;
//wcex.hbrBackground = CreateSolidBrush(RGB(255,0,0));
    wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);       //背景采用白/黑色
    wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
    wndclass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
    wndclass.hInstance=hInstance;
    wndclass.lpfnWndProc=WindowProc;
    wndclass.lpszClassName="abc";
    wndclass.lpszMenuName=NULL;
    wndclass.style=0;    //RegisterClass(&wndclass);
if (!RegisterClass(&wndclass))
{
MessageBeep(0);
return FALSE;
}
    hwnd=CreateWindow("abc","绘图",WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,0,600,450,NULL,NULL,hInstance,NULL);    ShowWindow(hwnd,SW_SHOWNORMAL);
    UpdateWindow(hwnd);    while(GetMessage(&Msg,hwnd,NULL,0))
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
//return 0;
    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
)
{
    HDC hdc;                                   
    HBRUSH hBrush;
    HPEN hpen;                                   
    PAINTSTRUCT ps;
    

int nCenterX,nCenterY;                     
     switch(uMsg)
    {
    case WM_PAINT:
        hdc=BeginPaint(hwnd,&ps);
        SetMapMode(hdc,MM_ANISOTROPIC);
        SetWindowExtEx(hdc,400,300,NULL);
        SetViewportExtEx(hdc,600,450,NULL);
        SetViewportOrgEx(hdc,300,200,NULL);                                                                         //绘图开始
//     绘制圆
        hpen=CreatePen(PS_SOLID,1,RGB(80,53,192));                        //好看的（255,0,255）（）（）（）（）（）
        SelectObject(hdc,hpen);
{                                                                  //由于是在case 语句中for外面要加{}
for (int i=0;i<120;i++)
{
  int j,k;
 // Ellipse(hdc,-10-i,-10-i,10+i,10+i);
      //Sleep(300);
Ellipse(hdc,-10-i,-10-i,10+i,10+i);
Sleep(10);
while(i%5==0)
{
for (j=i;j<120;j++)
{
Ellipse(hdc,-10-j,-10-j,10+j,10+j);
Sleep(10);
}
}

}

}  
        //Sleep(100);
        InvalidateRect(hwnd,NULL,1);
        EndPaint(hwnd,&ps);        return 0;
    case WM_CLOSE:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd,uMsg,wParam,lParam);
    }
    return 0;
}