C# 禁止系统菜单按钮

using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data;using System.Diagnostics; namespace System{/// <summary>/// Form1 的摘要说明。/// </summary>public class Form1 : System.Windows.Forms.Form{private System.Windows.Forms.Button button1;private System.Windows.Forms.Button button2;/// <summary>/// 必需的设计器变量。/// </summary>private System.ComponentModel.Container components = null;public Form1(){//// Windows 窗体设计器支持所必需的//InitializeComponent();//// TODO: 在 InitializeComponent 调用后添加任何构造函数代码//}/// <summary>/// 清理所有正在使用的资源。/// </summary>protected override void Dispose( bool disposing ){if( disposing ){if (components != null) {components.Dispose();}}base.Dispose( disposing );}#region Windows 窗体设计器生成的代码/// <summary>/// 设计器支持所需的方法 - 不要使用代码编辑器修改/// 此方法的内容。/// </summary>private void InitializeComponent(){this.button1 = new System.Windows.Forms.Button();this.button2 = new System.Windows.Forms.Button();this.SuspendLayout();// // button1// this.button1.Location = new System.Drawing.Point(72, 32);this.button1.Name = "button1";this.button1.Size = new System.Drawing.Size(144, 23);this.button1.TabIndex = 0;this.button1.Text = "禁止系统菜单按钮命令";this.button1.Click = new System.EventHandler(this.button1_Click);// // button2// this.button2.Location = new System.Drawing.Point(72, 64);this.button2.Name = "button2";this.button2.Size = new System.Drawing.Size(144, 23);this.button2.TabIndex = 1;this.button2.Text = "允许系统菜单按钮命令";this.button2.Click = new System.EventHandler(this.button2_Click);// // Form1// this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);this.ClientSize = new System.Drawing.Size(296, 126);this.Controls.Add(this.button2);this.Controls.Add(this.button1);this.MaximizeBox = false;this.Name = "Form1";this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;this.Text = "演示禁止系统菜单按钮命令";this.ResumeLayout(false);}#endregion/// <summary>/// 应用程序的主入口点。/// </summary>[STAThread]static void Main() {Application.Run(new Form1());}private int iClose=0;private const int WM_SYSCOMMAND=0x0112;protected override void WndProc(ref Message SystemMessage){//处理系统消息switch(SystemMessage.Msg){case WM_SYSCOMMAND:if(iClose==0)base.WndProc(ref SystemMessage);break;default:base.WndProc(ref SystemMessage);break;}}private void button1_Click(object sender, System.EventArgs e){//禁止系统菜单按钮命令this.iClose=1;MessageBox.Show("已经禁止系统菜单按钮命令！","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information);}private void button2_Click(object sender, System.EventArgs e){//允许系统菜单按钮命令this.iClose=0;MessageBox.Show("已经允许系统菜单按钮命令！","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information);}}}