从Unity窗口获取WM_INPUT

using System.Runtime.InteropServices;

public static class WinAPI
{
    // 声明Windows API函数
    [DllImport("user32.dll")]
    public static extern IntPtr GetForegroundWindow();

    [DllImport("user32.dll")]
    public static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);

    [DllImport("user32.dll")]
    public static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);

    [DllImport("user32.dll")]
    public static extern int CallWindowProc(IntPtr lpPrevWndFunc, IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
}

using UnityEngine;
using System;

public class InputManager : MonoBehaviour
{
    // 定义WM_INPUT消息的常量
    private const int WM_INPUT = 0x00FF;

    // 定义处理WM_INPUT消息的回调函数
    private IntPtr WindowProc(IntPtr hwnd, uint msg, IntPtr wParam, IntPtr lParam)
    {
        // 处理WM_INPUT消息的逻辑代码
        // ...

        // 调用默认的窗口处理函数
        return WinAPI.CallWindowProc(IntPtr.Zero, hwnd, msg, wParam, lParam);
    }

    private void Start()
    {
        // 获取Unity窗口的句柄
        IntPtr hwnd = WinAPI.GetForegroundWindow();

        // 获取窗口的原始消息处理函数
        IntPtr prevWndProc = WinAPI.GetWindowLong(hwnd, -4);

        // 设置新的消息处理函数
        WinAPI.SetWindowLong(hwnd, -4, Marshal.GetFunctionPointerForDelegate(new WinAPI.WndProc(WindowProc)));
    }
}