c 中的 Winapi Window 没有响应

Question

我一直在尝试使用 WinAPI 制作一个简单的 window，它编译并 links 带有一些警告，当我打开程序时 window 出现了，但是当我尝试与它交互时，会播放 windows 警告音，它不允许我使用 window，甚至无法关闭它，我必须使用任务管理器。

为了编译它，我在命令行中使用了微软的“cl.exe”：

cl /c window.c

警告是：

window.c(39): warning C4133: 'function': incompatible types, from 'LPSTR' to 'HINSTANCE'
window.c(40): warning C4133: 'function': incompatible types, from 'LPSTR' to 'HINSTANCE'
window.c(41): warning C4047: '=': 'HBRUSH' differs in levels of indirection from 'int'

至 link 我在命令行中使用 crinkler：

crinkler /NODEFAULTLIB /ENTRY:main /SUSBYSTEM:WINDOWS /TINYHEADER /TINYIMPORT /OUT:c.exe window.obj kernel32.lib user32.lib

警告是：

: warning LNK: Entry point not at start of section, jump necessary

我使用的代码是：

#include <windows.h>

#define WINDOW_STYLE        WS_VISIBLE+WS_OVERLAPPEDWINDOW-WS_THICKFRAME-WS_MAXIMIZE
#define WINDOW_WIDTH        640
#define WINDOW_HEIGHT       480

static const char* window_name = "My Window";
RECT window_rect = {0, 0, WINDOW_HEIGHT, WINDOW_WIDTH};

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uMsg)
    {
    case WM_CLOSE:
        PostQuitMessage(0);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    }

    return DefWindowProcA(hwnd, uMsg, wParam, lParam);
}

int main()
{
    int ret = 0;
    HMODULE instance = GetModuleHandleA(NULL);

    AdjustWindowRect(&window_rect, WINDOW_STYLE, FALSE);

    WNDCLASSEXA window_class;
    window_class.cbSize = 48;
    window_class.style = CS_OWNDC|CS_HREDRAW|CS_VREDRAW;
    window_class.lpfnWndProc = WindowProc;
    window_class.cbClsExtra = 0;
    window_class.cbWndExtra = 0;
    window_class.hInstance = instance;
    window_class.hIcon = LoadIconA(IDI_APPLICATION, 0);
    window_class.hCursor = LoadCursorA(IDI_APPLICATION, 0);
    window_class.hbrBackground = COLOR_WINDOW;
    window_class.lpszMenuName = 0;
    window_class.lpszClassName = window_name;
    window_class.hIconSm = 0;

    if (RegisterClassExA(&window_class)) {

        HWND window = CreateWindowExA(
            0,
            window_name,
            window_name,
            WINDOW_STYLE,
            CW_USEDEFAULT,
            CW_USEDEFAULT,
            window_rect.right - window_rect.left,
            window_rect.bottom - window_rect.top,
            0,
            0,
            instance,
            NULL);

        ShowWindow(window, SW_SHOW);
        UpdateWindow(window);

        MSG msg;

        while(1)
        {
            if (PeekMessageA(&msg, 0, 0, 0, PM_REMOVE)) {
                if (msg.message == WM_QUIT) {
                    ExitProcess(0);
                    break;
                } else {
                    TranslateMessage(&msg);
                    DispatchMessage(&msg);
                }
            }
        }
    } else {
        ret = 1;
    }

    ExitProcess(0);

    return ret;
}

有人知道怎么解决吗？谢谢。

Answer 1

以下行与您认为的不一样：

#define WINDOW_STYLE WS_VISIBLE+WS_OVERLAPPEDWINDOW-WS_THICKFRAME-WS_MAXIMIZE

虽然有点常见，有时甚至会产生正确的值，但它是一种非常脆弱的位操作实现方式。在这种特殊情况下，表达式扩展为：

0x10000000L + 0x00CF0000L - 0x00040000L - 0x01000000L

这会产生值 0xFFCB0000L¹（由于不小心使用 WS_MAXIMIZE 而不是 WS_MAXIMIZEBOX）。这转换为具有以下样式的 window：

WS_POPUP
WS_CHILD（注意，这已经与 WS_POPUP 互斥了）
WS_ICONIC
WS_VISIBLE
WS_DISABLED
...

作为documented:

WS_DISABLED: The window is initially disabled. A disabled window cannot receive input from the user. To change this after a window has been created, use the EnableWindow function.

这就解释了为什么您无法与您的 window 互动。解决方法很简单：使用按位运算符进行位操作而不是算术运算符：

#define WINDOW_STYLE (WS_VISIBLE | WS_OVERLAPPEDWINDOW & ~WS_THICKFRAME & ~WS_MAXIMIZE)

¹ 撇开有符号溢出的行为未定义这一事实。

c 中的 Winapi Window 没有响应

Winapi Window in c not responding

c

windows

winapi

window

cl