错误 LNK2001：无法解析的外部符号 WINAPI

Question

这是我第一次学习 WINAPI 编码，所以我不明白我遇到了什么错误。

error LNK2001: unresolved external symbol "long stdcall WinProc(struct HWND *,unsigned int,unsigned int,long)" (?WinProc@@YGJPAUHWND__@@IIJ@Z) Please help me.

#include <Windows.h>

LRESULT CALLBACK WinProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPreInstance, PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT("HelloWorld");
HWND hwnd;
MSG msg;
WNDCLASS wndclass;
wndclass.style = CS_HREDRAW|CS_VREDRAW;
wndclass.lpfnWndProc = WinProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
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 requires Windows"), szAppName,MB_ICONERROR);
    return 0;
}
hwnd = CreateWindow(szAppName,TEXT("The hello World 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 msg, WPARAM wParam,LPARAM lParam)
{
HDC hdc;
PAINTSTRUCT ps;
RECT rect;
switch(msg)
{
case WM_CREATE:
    return 0;
case WM_PAINT:
    hdc = BeginPaint(hwnd,&ps);
    GetClientRect(hwnd,&rect);
    DrawText(hdc,TEXT("Hello World"),-1,&rect,DT_SINGLELINE|DT_CENTER|DT_VCENTER);
    EndPaint(hwnd,&ps);
    return 0;
case WM_DESTROY:
    PostQuitMessage(0);
    return 0;
}
return DefWindowProc(hwnd,msg,wParam,lParam);
}

int main()
{
MessageBox(NULL, "Hello, world!", "Hello world", MB_OK);
}

非常感谢。

Answer 1

检查你的拼写。您声明了一个名为 WinProc 的函数，但其实现名为 WndProc.

您声明并使用了这个：

LRESULT CALLBACK WinProc(HWND, UINT, WPARAM, LPARAM);
//...
wndclass.lpfnWndProc = WinProc;

但是你有这个作为实际功能：

LRESULT CALLBACK WndProc (HWND hwnd, UINT msg, WPARAM wParam,LPARAM lParam)

错误 LNK2001：无法解析的外部符号 WINAPI

error LNK2001: unresolved external symbol WINAPI

c++

winapi

visual-studio-2010