初学者对此问题实在百思不得其解,请大侠指教!

Question

我从书上抄了个基本的图形程序,结果编译通过,链接出错:exp1.obj : error LNK2001: unresolved external symbol "int __cdecl InitWindowsClass(struct HINSTANCE__ *)" (?InitWindowsClass@@YAHPAUHINSTANCE__@@@Z)这是它的源码,有谁能告诉我是什么原因.
#include <windows.h>
#include <stdlib.h>
#include <string.h>long WINAPI WndProc
(
 HWND hWnd,
 UINT iMessage,
 UINT wParam,
 LONG lParam
 );BOOL InitWindowsClass(HINSTANCE hInstance);
BOOL InitWindows(HINSTANCE hInstance,int nCmdShow);
HWND hWndMain;int WINAPI WinMain
(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow
)
{
    MSG Message;
    if(!InitWindowsClass(hInstance))
        return FALSE;
    if(!InitWindows(hInstance,nCmdShow))
        return FALSE;
    while(GetMessage(&Message,0,0,0))
    {
        TranslateMessage(&Message);
        DispatchMessage(&Message);
    }
    return Message.wParam;
}long WINAPI WndProc
    (
    HWND hWnd,
    UINT iMessage,
    UINT wParam,
    LONG lParam
    )
{
    HDC hDC;
    HBRUSH hBrush;
    HPEN hPen;
    PAINTSTRUCT PtStr;
    switch(iMessage)
    {
case WM_PAINT:
hDC=BeginPaint(hWnd,&PtStr);
SetMapMode(hDC,MM_ANISOTROPIC);
hPen=(HPEN)GetStockObject(BLACK_PEN); hBrush=(HBRUSH)GetStockObject(DKGRAY_BRUSH); SelectObject(hDC,hBrush);
SelectObject(hDC,hPen);
RoundRect(hDC,50,120,100,200,15,15);
hBrush=(HBRUSH)GetStockObject(LTGRAY_BRUSH); SelectObject(hDC,hBrush);
Ellipse(hDC,150,50,200,150);
hBrush=(HBRUSH)GetStockObject(HOLLOW_BRUSH);
SelectObject(hDC,hBrush);
Pie(hDC,250,50,300,100,250,50,300,50);
EndPaint(hWnd,&PtStr);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
return(DefWindowProc(hWnd,iMessage,wParam,lParam));
}
}BOOL InitWindows(HINSTANCE hInstance ,int nCmdShow)
{
HWND hWnd;
hWnd=CreateWindow("WinFill",
  "填充示例程序 ",
  WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT,
  0,
  CW_USEDEFAULT,
  0,
  NULL,
  NULL,
  hInstance,
  NULL);
if(!hWnd)
return FALSE;
hWndMain=hWnd;
ShowWindow(hWnd,nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}BOOL InitWindowClass(HINSTANCE hInstance)
{
WNDCLASS WndClass;
WndClass.cbClsExtra=0;
WndClass.cbWndExtra=0;
WndClass.hbrBackground=(HBRUSH)(GetStockObject(WHITE_BRUSH));
WndClass.hCursor=LoadCursor(NULL,IDC_ARROW);
WndClass.hIcon=LoadIcon(NULL,"END");
WndClass.hInstance=hInstance;
WndClass.lpfnWndProc=WndProc;
WndClass.lpszClassName="WinFill";
WndClass.lpszMenuName=NULL;
WndClass.style=CS_HREDRAW|CS_VREDRAW;
return RegisterClass(&WndClass);
}

Answer 1

这是声明和定义，对比一下看看？
BOOL InitWindowsClass(HINSTANCE hInstance);
BOOL InitWindowClass(HINSTANCE hInstance)
{
 .......
}