为什么没有运行结果？没有窗口弹出！而且似乎是停在了UpdateWindow处就不走了
#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("HellowWin");
    HWND hwnd;
    MSG msg;
    WNDCLASS wndclass;
    wndclass.style         =CS_HREDRAW|CS_VREDRAW;
    wndclass.cbClsExtra    =0;
    wndclass.cbWndExtra    =0;
    wndclass.hbrBackground =(HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.hCursor       =LoadCursor(NULL,IDC_ARROW) ;
    wndclass.hIcon         =LoadCursor(NULL,IDI_APPLICATION);
    wndclass.hInstance     =hInstance;
    wndclass.lpfnWndProc   =WndProc;
    wndclass.lpszClassName =szAppName;
    wndclass.lpszMenuName  =NULL;
   

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

    hwnd=CreateWindow(szAppName,
        TEXT("The Hello Program"),
        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;
}

LRESULT CALLBACK WndProc (HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;

    switch(message)
    {
      
      case WM_PAINT:
          hdc=BeginPaint(hwnd,&ps);

          GetClientRect(hwnd,&rect);

          DrawText(hdc,"HEllo World",-1,&rect,DT_SINGLELINE|DT_CENTER|DT_VCENTER);
          EndPaint(hwnd,&ps);
        return 0;
      case WM_DESTROY:
          PostQuitMessage(0);
        return 0;
      default :
          return DefWindowProc(hwnd,message,wParam,wParam);
    }
    return 0;
}