#include <windows.h>
#include <stdio.h>
LRESULT CALLBACK WinSunProc(
     HWND hwnd,
     UINT uMsg,
     WPARAM wParam,
     LPARAM lParam
);
int WINAPI WinMain(
  HINSTANCE hInstance,      // handle to current instance
  HINSTANCE hPrevInstance,  // handle to previous instance
  LPSTR lpCmdLine,          // command line
  int nCmdShow              // show state
)
{
    WNDCLASS wndcls;
    wndcls.cbClsExtra=0;
    wndcls.cbWndExtra=0;
    wndcls.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH);
    wndcls.hCursor=LoadCursor(NULL,IDI_ERROR);
    wndcls.hIcon=LoadIcon(NULL,IDI_ERROR);
    wndcls.hInstance=hInstance;
    wndcls.lpfnWndProc=WinSunProc;
    wndcls.lpszClassName="Weixin2003";
    wndcls.lpszMenuName=NULL;
    wndcls.style=CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&wndcls);

    HWND hwnd;
    hwnd=CreateWindow("Weixin2003","214646321454",WS_OVERLAPPEDWINDOW,0,0,200,200,NULL,NULL,hInstance,NULL);

    ShowWindow(hwnd,SW_SHOWNORMAL);
    UpdateWindow(hwnd);

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

LRESULT CALLBACK WinSunProc(
     HWND hwnd,
     UINT uMsg,
     WPARAM wParam,
     LPARAM lParam
)
{
    switch(uMsg)
    {
    case WM_CHAR:
        char szChar[20];
        sprintf(szChar,"char is %d",wParam);
        MessageBox(hwnd,szChar,"weixin1",0);
        break;
    case WM_LBUTTONDOWN:
        MessageBox(hwnd,"mouse clicked","weixin2",0);
        HDC hdc;
        hdc=GetDC(hwnd);
        TextOut(hwnd,0,50,"465446",strlen("465446"));
        ReleaseDC(hwnd,hdc);
        break;
    case WM_PAINT:
        HDC hDC;
        PAINTSTRUCT ps;
        hDC=BeginPaint(hwnd,&ps);
        TextOut(hDC,0,0,"787997",strlen("787997"));
        EndPaint(hwnd,&ps);
        break;
    case WM_CLOSE:
        if(IDYES==MessageBox(hwnd,"是真要退出？"，"Weixin",MB_YESNO))
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd,uMsg,wParam,lParam);
         
    }
    return 0;
}

}

--------------------Configuration: WinMain - Win32 Debug--------------------
Compiling...
WinMain.cpp
D:\VC\WinMain\WinMain.cpp(49) : error C2601: 'WinSunProc' : local function definitions are illegal
D:\VC\WinMain\WinMain.cpp(72) : error C2018: unknown character '0xa3'
D:\VC\WinMain\WinMain.cpp(72) : error C2018: unknown character '0xac'
执行 cl.exe 时出错.

WinMain.exe - 1 error(s), 0 warning(s)
这里为什么说WinSunProc是非法定义呢？像这样的问题又要如何去找错误在哪里并改过来呢！我希望高手能告诉我方法。

#include <windows.h>
#include <stdio.h>
LRESULT CALLBACK WinSunProc(
     HWND hwnd, 
     UINT uMsg, 
     WPARAM wParam, 
     LPARAM lParam
);
int WINAPI WinMain(
  HINSTANCE hInstance,      // handle to current instance
  HINSTANCE hPrevInstance,  // handle to previous instance
  LPSTR lpCmdLine,          // command line
  int nCmdShow              // show state
)
{
    WNDCLASS wndcls;
    wndcls.cbClsExtra=0;
    wndcls.cbWndExtra=0;
    wndcls.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH);
    wndcls.hCursor=LoadCursor(NULL,IDI_ERROR);
    wndcls.hIcon=LoadIcon(NULL,IDI_ERROR);
    wndcls.hInstance=hInstance;
    wndcls.lpfnWndProc=WinSunProc;
    wndcls.lpszClassName="Weixin2003";
    wndcls.lpszMenuName=NULL;
    wndcls.style=CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&wndcls);

    HWND hwnd;
    hwnd=CreateWindow("Weixin2003","214646321454",WS_OVERLAPPEDWINDOW,0,0,200,200,NULL,NULL,hInstance,NULL);

    ShowWindow(hwnd,SW_SHOWNORMAL);
    UpdateWindow(hwnd);

    MSG msg;
    while(GetMessage(&msg,NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}                                     //注意这里

LRESULT CALLBACK WinSunProc(
     HWND hwnd, 
     UINT uMsg, 
     WPARAM wParam, 
     LPARAM lParam
)
{
    switch(uMsg)
    {
    case WM_CHAR:
        char szChar[20];
        sprintf(szChar,"char is %d",wParam);
        MessageBox(hwnd,szChar,"weixin1",0);
        break;
    case WM_LBUTTONDOWN:
        MessageBox(hwnd,"mouse clicked","weixin2",0);
        HDC hdc;
        hdc=GetDC(hwnd);
        TextOut(hwnd,0,50,"465446",strlen("465446"));
        ReleaseDC(hwnd,hdc);
        break;
    case WM_PAINT:
        HDC hDC;
        PAINTSTRUCT ps;
        hDC=BeginPaint(hwnd,&ps);
        TextOut(hDC,0,0,"787997",strlen("787997"));
        EndPaint(hwnd,&ps);
        break;
    case WM_CLOSE:
        if(IDYES==MessageBox(hwnd,"是真要退出？"，"Weixin",MB_YESNO))
        {
            DestroyWindow(hwnd);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd,uMsg,wParam,lParam);
         
    }
    return 0;
}

函数不能嵌套定义。可以调用。

函数不能嵌套定义！
这个值得注意！