c++ - 我用 c 编写了一些代码来制作简单的 win32 窗口，但失败了

Question

我收到此错误:

LNK1120:第 1 行有 1 个未解析的外部

错误 LNK2019:函数 _WinMain@16 C:\Users\giorgi\Documents\Visual Studio 2013\Projects\Hello\Hello\Source.obj Hello 中引用了无法解析的外部符号 _winproc@20

我是 WinApi 新手，请帮忙。

#include <windows.h>


LRESULT CALLBACK winproc(WNDPROC lpPrevWndFunc, HWND hwnd, UINT msg, WPARAM wp, LPARAM lp);


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR LpCmdLine, int nCmdShow)
{

WNDCLASSEX class;
ZeroMemory(&class, sizeof(WNDCLASSEX));

class.cbSize = sizeof(WNDCLASSEX);
class.style = CS_HREDRAW | CS_VREDRAW;
class.lpfnWndProc = (WNDPROC)winproc;
class.cbClsExtra = 0;
class.cbWndExtra = 0;
class.hInstance = hInstance;
class.hIcon = NULL;
class.hCursor = LoadCursor(NULL, IDC_ARROW);
class.hbrBackground = (HBRUSH)COLOR_WINDOW;
class.lpszClassName = "window class";
class.lpszMenuName = NULL;
class.hIconSm = NULL;

RegisterClassEx(&class);



HWND hwnd = CreateWindowEx
    (
    WS_EX_ACCEPTFILES,
    "window class",
    "window",
    WS_OVERLAPPED,
    200,
    200,
    800,
    600,
    NULL,
    NULL,
    hInstance,
    NULL
    );


ShowWindow(hwnd, nCmdShow);


MSG msg;
ZeroMemory(&msg, sizeof(MSG));


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

return 0;
}


LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
{
switch (msg)
{
case WM_DESTROY:
{
    PostQuitMessage(0);
    return 0;
}
    break;
}

return DefWindowProc(hwnd, msg, wp, lp);

}

Answer 1

正如其他人所说，C 区分大小写，因此 winproc 和 WinProc 将是两个不同的函数。您还需要确保 Windows 过程的签名与 Windows 期望的相符，因此请进行以下更改:

1. 将 LRESULT CALLBACK winproc(WNDPROC lpPrevWndFunc, HWND hwnd, UINT msg, WPARAM wp, LPARAM lp); 更改为 LRESULT CALLBACK winProc(HWND, UINT, WPARAM, LPARAM) ;

2. 将 class.lpfnWndProc = (WNDPROC)winproc; 更改为 class.lpfnWndProc = (WNDPROC)winProc;

3. 将 LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) 更改为 LRESULT CALLBACK winProc(HWND hwnd, UINT mgs, WPARAM wp, LPARAM lp)

最后，自从我在 win32-API 级别编程以来已经有一段时间了，但我相信您的 Windows 程序应该如下所示:

    LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
    {
        switch (msg)
        {
            case WM_DESTROY:
            {
                PostQuitMessage(0);
                return 0;
            }
            break;

            default:
                return DefWindowProc(hwnd, msg, wp, lp);
        }
    }

换句话说，如果您自己不处理该消息，您只想返回默认窗口过程 (DefWindowProc)。