如何用代码实现禁止使用截屏键 要有代码示例

下面是一个使用 C# 语言实现的禁用截屏键的示例代码：

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace DisablePrintScreen
{
    public partial class Form1 : Form
    {
        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private const int VK_SNAPSHOT = 0x2C;

        private readonly LowLevelKeyboardProc _proc;
        private readonly IntPtr _hookId;

        public Form1()
        {
            InitializeComponent();

            // 注册系统钩子
            _proc = HookCallback;
            _hookId = SetHook(_proc);
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            // 注销系统钩子
            UnhookWindowsHookEx(_hookId);
        }

        private IntPtr SetHook(LowLevelKeyboardProc proc)
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0);
            }
        }

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

        private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
            {
                int vkCode = Marshal.ReadInt32(lParam);
                if (vkCode == VK_SNAPSHOT)
                {
                    // 拦截截屏键消息
                    return (IntPtr)1;
                }
            }
            return CallNextHookEx(_hookId, nCode, wParam, lParam);
        }

        #region Windows API

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

        [DllImport("user32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool UnhookWindowsHookEx(IntPtr hhk);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);

        #endregion
    }
}

上述代码中，`SetHook` 方法用于注册系统钩子，`HookCallback` 方法是自定义的钩子函数，当截屏键被按下时，会拦截消息并返回 1。在窗体关闭时，需要调用 `UnhookWindowsHookEx` 方法注销系统钩子。