低级键盘挂钩上的 ExecutionEngineException

Question

我目前正在尝试使用 wpf 使 Global LowLevel 键盘挂钩在 .net 5 中工作，但一段时间后我总是得到 ExecutionEngineException 并且我的应用程序崩溃了。 According to the docs，这个异常根本不应该再发生，但对我来说它确实发生了。它也不是特定于我的项目，因为最小的 WPF .net 5 项目也会在一些关键混搭后崩溃。

有没有人知道如何解决或绕过这个问题？

主要示例代码 Window:

public partial class MainWindow : Window {
    private const int WH_KEYBOARD_LL = 13;
    private const int WM_KEYDOWN = 0x0100;
    private const int WM_SYSKEYDOWN = 0x0104;

    private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod,
        uint dwThreadId);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
        IntPtr wParam, IntPtr lParam);
    
    [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Ansi)]
    static extern IntPtr LoadLibrary([MarshalAs(UnmanagedType.LPStr)] string lpFileName);


    private IntPtr _hook;


    public bool Hook() {
        if (_hook == IntPtr.Zero) {
            var modPtr = LoadLibrary("user32.dll");

            _hook = SetWindowsHookEx(WH_KEYBOARD_LL, Handler, modPtr, 0);
        }

        return _hook != IntPtr.Zero;
    }

    private IntPtr Handler(int code, IntPtr param, IntPtr lParam) {
        return CallNextHookEx(_hook, code, param, lParam);
    }

    public MainWindow() {
        InitializeComponent();
        Hook();
    }
}

我得到的调用栈：

WindowsBase.dll!System.Windows.Threading.Dispatcher.GetMessage(ref System.Windows.Interop.MSG msg, System.IntPtr hwnd, int minMessage, int maxMessage)
WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame frame)
WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrame(System.Windows.Threading.DispatcherFrame frame)
WindowsBase.dll!System.Windows.Threading.Dispatcher.Run()
PresentationFramework.dll!System.Windows.Application.RunDispatcher(object ignore)
PresentationFramework.dll!System.Windows.Application.RunInternal(System.Windows.Window window)
PresentationFramework.dll!System.Windows.Application.Run()
EngineExecutionError.dll!EngineExecutionError.App.Main()

Answer 1

正如评论所指出的，您不应将 lambda 或委托直接传递给 Win32 Api 调用（或任何 C api 调用）。解决方法是创建一个包含对函数的引用的静态变量

private static LowLevelKeyboardProc _handler = Handler;
[...]
_hook = SetWindowsHookEx(WH_KEYBOARD_LL, _handler, modPtr, 0);

或者固定委托，这样 CLR 就不会移动它，这是我选择的。

private LowLevelKeyboardProc _handler;
private GCHandle _gcHandler;

public KeyboardHook() {
    _handler = Handler;
    _gcHandler = GCHandle.Alloc(_handler);
}

[...]

_hook = SetWindowsHookEx(WH_KEYBOARD_LL, _handler, modPtr, 0);

对于低级挂钩，您似乎可以将 modPtr 设置为 LoadLibrary("user32.dll")、GetModuleHandle(null) 或 IntPtr.Zero。似乎与所有这些一起工作。

低级键盘挂钩上的 ExecutionEngineException

ExecutionEngineException on LowLevel Keyboard Hook

c#

wpf

winapi

.net-5