事件处理方法将在触发事件的线程中运行，就是说处理方法和事件源会在同一线程

这是测试程序界面。

  1using System;
  2using System.Drawing;
  3using System.Collections;
  4using System.ComponentModel;
  5using System.Windows.Forms;
  6using System.Data;
  7
  8using System.Threading;
  9
 10namespace ThreadCrossEventHandler
 11{
 12    /**//// <summary>
 13    /// Form1 的摘要说明。
 14    /// </summary>
 15    public class Form1 : System.Windows.Forms.Form
 16    {
 17        /**//// <summary>
 18        /// 必需的设计器变量。
 19        /// </summary>
 20        private System.ComponentModel.Container components = null;
 21        private System.Windows.Forms.Button button1;
 22        private System.Windows.Forms.Button button2;
 23        private System.Windows.Forms.RichTextBox richTxtMainThreadEventHandler;
 24        private System.Windows.Forms.RichTextBox richTxtCallerEventHandler;
 25
 26        private MainThreadEvnetHandler mainThreadEvent;        
 27        private bool _tigerEvnetInCaller = false;
 28
 29        public Form1()
 30        {            
 31            InitializeComponent();
 32        }
 33
 34        /**//// <summary>
 35        /// 清理所有正在使用的资源。
 36        /// </summary>
 37        protected override void Dispose( bool disposing )
 38        {
 39            if( disposing )
 40            {
 41                if (components != null) 
 42                {
 43                    components.Dispose();
 44                }
 45            }
 46            base.Dispose( disposing );
 47        }
 48
 49        Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码
 50        /**//// <summary>
 51        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
 52        /// 此方法的内容。
 53        /// </summary>
 54        private void InitializeComponent()
 55        {
 56            this.button1 = new System.Windows.Forms.Button();
 57            this.button2 = new System.Windows.Forms.Button();
 58            this.richTxtMainThreadEventHandler = new System.Windows.Forms.RichTextBox();
 59            this.richTxtCallerEventHandler = new System.Windows.Forms.RichTextBox();
 60            this.SuspendLayout();
 61            // 
 62            // button1
 63            // 
 64            this.button1.Location = new System.Drawing.Point(96, 16);
 65            this.button1.Name = "button1";
 66            this.button1.Size = new System.Drawing.Size(128, 23);
 67            this.button1.TabIndex = 0;
 68            this.button1.Text = "在主线程触发事件";
 69            this.button1.Click += new System.EventHandler(this.button1_Click);
 70            // 
 71            // button2
 72            // 
 73            this.button2.Location = new System.Drawing.Point(416, 16);
 74            this.button2.Name = "button2";
 75            this.button2.Size = new System.Drawing.Size(128, 23);
 76            this.button2.TabIndex = 1;
 77            this.button2.Text = "在子线程触发事件";
 78            this.button2.Click += new System.EventHandler(this.button2_Click);
 79            // 
 80            // richTxtMainThreadEventHandler
 81            // 
 82            this.richTxtMainThreadEventHandler.Location = new System.Drawing.Point(8, 56);
 83            this.richTxtMainThreadEventHandler.Name = "richTxtMainThreadEventHandler";
 84            this.richTxtMainThreadEventHandler.Size = new System.Drawing.Size(296, 256);
 85            this.richTxtMainThreadEventHandler.TabIndex = 2;
 86            this.richTxtMainThreadEventHandler.Text = "";
 87            // 
 88            // richTxtCallerEventHandler
 89            // 
 90            this.richTxtCallerEventHandler.Location = new System.Drawing.Point(312, 56);
 91            this.richTxtCallerEventHandler.Name = "richTxtCallerEventHandler";
 92            this.richTxtCallerEventHandler.Size = new System.Drawing.Size(312, 256);
 93            this.richTxtCallerEventHandler.TabIndex = 3;
 94            this.richTxtCallerEventHandler.Text = "";
 95            // 
 96            // Form1
 97            // 
 98            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
 99            this.ClientSize = new System.Drawing.Size(632, 317);
100            this.Controls.Add(this.richTxtCallerEventHandler);
101            this.Controls.Add(this.richTxtMainThreadEventHandler);
102            this.Controls.Add(this.button2);
103            this.Controls.Add(this.button1);
104            this.Name = "Form1";
105            this.Text = "Form1";
106            this.Load += new System.EventHandler(this.Form1_Load);
107            this.ResumeLayout(false);
108
109        }
110        #endregion
111
112        /**//// <summary>
113        /// 应用程序的主入口点。
114        /// </summary>
115        [STAThread]
116        static void Main() 
117        {
118            Application.Run(new Form1());
119        }
120
121        private void Form1_Load(object sender, System.EventArgs e)
122        {
123            mainThreadEvent += new MainThreadEvnetHandler(this.MainThreadEvnetProcess);
124
125            Thread.CurrentThread.Name = "Main";
126            Thread caller = new Thread(new System.Threading.ThreadStart(this.ThreadMethod));
127            caller.Name = "Caller";
128            caller.IsBackground = true;
129            caller.Start();            
130        }
131
132        private void ThreadMethod()
133        {
134            WriteMessage(Thread.CurrentThread.Name,
135                string.Format("{0} thread is started",Thread.CurrentThread.Name));
136            while(true)
137            {
138                if(_tigerEvnetInCaller)
139                {
140                    TigerEvent();
141                    _tigerEvnetInCaller = false;
142                }
143            }
144        }
145
146        private void MainThreadEvnetProcess(object sender, EventArgs e)
147        {
148            WriteMessage(Thread.CurrentThread.Name,
149                string.Format("Event handler is processed in thread {0}", Thread.CurrentThread.Name));
150        }
151
152        private void button1_Click(object sender, System.EventArgs e)
153        {
154            TigerEvent();
155        }
156
157        private void TigerEvent()
158        {
159            WriteMessage(Thread.CurrentThread.Name, 
160                string.Format("事件在{0}中触发", Thread.CurrentThread.Name));
161            mainThreadEvent(this, new EventArgs());
162        }
163
164        private void WriteMessage(string threadName, string message)
165        {
166            if(threadName.Equals("Main"))
167                richTxtMainThreadEventHandler.AppendText(message + "\r\n");
168            else
169                richTxtCallerEventHandler.AppendText(message + "\r\n");
170        }
171
172        private void button2_Click(object sender, System.EventArgs e)
173        {
174            _tigerEvnetInCaller = true;
175        }
176    }
177
178    public delegate void MainThreadEvnetHandler(object sender, EventArgs e);
179}
180