请大家帮忙看看,为什么表是倒着的,请大家帮忙分析一下.

[antss]

#define ID_TIMER 1
#define TWOPI (2*3.14159)

#include<windows.h>
#include<math.h>

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)
{
static TCHAR szAppName[]=TEXT("WHATCLR");
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.hIcon =NULL;
wndclass.hCursor =LoadCursor(NULL,IDC_ARROW);
wndclass.hbrBackground =(HBRUSH)GetStockObject(WHITE_BRUSH);
wndclass.lpszMenuName =NULL;
wndclass.lpszClassName =szAppName;

if(!RegisterClass(&wndclass))
{
MessageBox(NULL,TEXT("The Program require Windows NT!"),szAppName,MB_ICONERROR);
return 0;
}

hWnd=CreateWindow(szAppName,
TEXT("CLOCK"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL);
ShowWindow(hWnd,nCmdShow);
UpdateWindow(hWnd);

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

return msg.wParam;
}

void Setlsotropic(HDC hdc,int cxClient,int cyClient)
{
SetMapMode(hdc,MM_ISOTROPIC);
SetWindowExtEx(hdc,1000,1000,NULL);
SetViewportExtEx(hdc,cxClient/2,cyClient/2,NULL);
SetViewportOrgEx(hdc,cxClient/2,cyClient/2,NULL);

}

void RotatePoint(POINT pt[],int iNum,int iAngle)
{
int i;
POINT ptTemp;
for(i=0;i<iNum;i++)
{
ptTemp.x=(int)(pt[i].x*cos(TWOPI*iAngle/360)-pt[i].y*sin(TWOPI*iAngle/360));
ptTemp.y=(int)(pt[i].y*cos(TWOPI*iAngle/360)-pt[i].x*sin(TWOPI*iAngle/360));
pt[i]=ptTemp;
}
}

void DrawClock(HDC hdc)
{
int iAngle;
POINT pt[3];
for(iAngle=0;iAngle<360;iAngle+=6)
{
pt[0].x=0;
pt[0].y=900;
RotatePoint(pt,1,iAngle);
pt[2].x=pt[2].y=iAngle%5?33:100;
pt[0].x-=pt[2].x/2;
pt[0].y-=pt[2].y/2;

pt[1].x=pt[0].x+pt[2].x;
pt[1].y=pt[0].y+pt[2].y;

SelectObject(hdc,GetStockObject(BLACK_BRUSH));
Ellipse(hdc,pt[0].x,pt[0].y,pt[1].x,pt[1].y);

}
}

void DrawHands(HDC hdc,SYSTEMTIME *pst,bool bChange)
{
static POINT pt[3][5]={
0,-150,100,0,0,600,-100,0,0,-150,
0,-200,50,0,0,800,-50,0,0,-200,
0,0,0,0,0,0,0,0,0,800
};

int i,iAngle[3];
POINT ptTemp[3][5];

iAngle[0]=(pst->wHour*30)%360+pst->wMinute/2;
iAngle[1]=pst->wMinute*6;
iAngle[2]=pst->wSecond*6;

memcpy(ptTemp,pt,sizeof(pt));

for(i=bChange?0:2;i<3;i++)
{
RotatePoint(ptTemp[i],5,iAngle[i]);
Polyline(hdc,ptTemp[i],5);
}
}
LRESULT CALLBACK WndProc(HWND hWnd,UINT message,WPARAM wParam,LPARAM lParam)
{
static int cxClient,cyClient;
static SYSTEMTIME stPrevious;
bool bChange;
HDC hdc;
PAINTSTRUCT ps;
SYSTEMTIME st;

switch(message)
{
case WM_CREATE:
SetTimer(hWnd,ID_TIMER,1000,NULL);
GetLocalTime(&st);
stPrevious=st;
return 0;

case WM_SIZE:
cxClient=LOWORD(lParam);
cyClient=HIWORD(lParam);
return 0;

case WM_TIMER:
GetLocalTime(&st);
bChange=st.wHour!=stPrevious.wHour||st.wMinute!=stPrevious.wMinute;
hdc=GetDC(hWnd);
Setlsotropic(hdc,cxClient,cyClient);
SelectObject(hdc,GetStockObject(WHITE_PEN));
DrawHands(hdc,&stPrevious,bChange);

SelectObject(hdc,GetStockObject(BLACK_PEN));
DrawHands(hdc,&st,true);

stPrevious=st;
return 0;

case WM_PAINT:
hdc=BeginPaint(hWnd,&ps);
Setlsotropic(hdc,cxClient,cyClient);
DrawClock(hdc);
DrawHands(hdc,&stPrevious,true);
EndPaint(hWnd,&ps);
return 0;

case WM_DESTROY:
KillTimer(hWnd,ID_TIMER);
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hWnd,message,wParam,lParam);
}

[lzr4304061988012]

SetViewportExtEx(hdc,-cxClient/2,-cyClient/2,NULL); //逻辑坐标与设备坐标的转化要正确。

[品茶]

void Setlsotropic(HDC hdc,int cxClient,int cyClient)函数中
将代码：

SetWindowExtEx(hdc,1000,1000,NULL);

改为：

SetWindowExtEx(hdc,-1000,-1000,NULL);

[antss]

谢谢二楼.

同时也谢谢一楼,谢谢.

万分感谢.