using System;

  using System.ComponentModel;

  using System.Threading;

  using System.Windows.Forms;

namespace CrossThreadDemo

{

    public partial class Form1 : Form

    {

        //设置这个委托支持异步调用文本框控件的文本属性。

        delegate void SetTextCallback(string text);

        //这个线程用于演示和线程安全的和不安全的方法来调用一个Windows窗体控件。

        private Thread demoThread = null;

        //这个BackgroundWorker用于演示执行异步操作, 推荐使用该方法。

        private BackgroundWorker backgroundWorker1;

        private TextBox textBox1;

        private Button setTextUnsafeBtn;

        private Button setTextSafeBtn;

        private Button setTextBackgroundWorkerBtn;

        public Form1()

        {

            InitializeComponent();

        }

        //这个事件处理程序创建一个线程,该线程演示用不安全的方式调用 Windows窗体, 在.net framework2.0后被禁用

        private void setTextUnsafeBtn_Click(object sender,EventArgs e)

        {

            this.demoThread = new Thread(new ThreadStart(this.ThreadProcUnsafe));

            this.demoThread.Start();

        }

   　　//这个方法执行工作线程, 文本框控件不安全的调用, 一执行就会报错.

        private void ThreadProcUnsafe()

        {

            //线程间操作无效: 从不是创建控件“textBox1”的线程访问它。

            this.textBox1.Text = "This text was set unsafely.";

        }

　　　　//这个事件处理程序创建一个线程,该线程使用安全的方式调用 Windows窗体.

        private void setTextSafeBtn_Click(object sender,EventArgs e)

        {

            this.demoThread = new Thread(new ThreadStart(this.ThreadProcSafe));

            this.demoThread.Start();

        }

        //这个方法执行工作线程,使 文本框控件的线程安全的调用.

        private void ThreadProcSafe()

        {

            this.SetText("This text was set safely.");

        }

        //这个方法演示了线程通过安全的模式, 调用一个Windows窗体控件。如果调用线程和当前创建了文本框控件的线程不用,该方法创建一个SetTextCallback,并使用了异步调用自身调用方法,
　　　　//如果调用线程创建的线程是一样的文本框控件,直接设置文本属性。

        private void SetText(string text)

        {

            if (this.textBox1.InvokeRequired)

            {

                SetTextCallback d = new SetTextCallback(SetText);

                this.Invoke(d, new object[] { text });

            }

            else

            {

                //在此设置textBox1的文本

                this.textBox1.Text = text;

            }

        }

        //这个事件处理程序通过调用RunWorkerAsync BackgroundWorker。设置文本框控件的文本属性, 用BackgroundWorker提高RunWorkerCompleted事件。

        private void setTextBackgroundWorkerBtn_Click(object sender,EventArgs e)

        {

            this.backgroundWorker1.RunWorkerAsync();

        }

        //这个事件处理程序设置文本框的文本属性控制。它调用创建的线程文本框控件,所以调用是线程安全的,异步执行BackgroundWorker是首选方法操作.

        private void backgroundWorker1_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e)

        {

            this.textBox1.Text ="This text was set safely by BackgroundWorker.";

        }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    static class Program

    {

        /// <summary>

        /// 应用程序的主入口点。

        /// </summary>

        [STAThread]

        static void Main()

        {

            Application.EnableVisualStyles();

            Application.SetCompatibleTextRenderingDefault(false);

            Application.Run(new CrossThreadDemo.Form1());

        }

    }

}

namespace CrossThreadDemo

{

    partial class Form1

    {

        /// <summary>

        /// 必需的设计器变量。

        /// </summary>

        private System.ComponentModel.IContainer components = null;

        /// <summary>

        /// 清理所有正在使用的资源。

        /// </summary>

        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>

        protected override void Dispose(bool disposing)

        {

            if (disposing && (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.textBox1 = new System.Windows.Forms.TextBox();

            this.setTextUnsafeBtn = new System.Windows.Forms.Button();

            this.setTextSafeBtn = new System.Windows.Forms.Button();

            this.setTextBackgroundWorkerBtn = new System.Windows.Forms.Button();

            this.backgroundWorker1 = new System.ComponentModel.BackgroundWorker();

            this.SuspendLayout();

            //

            // textBox1

            //

            this.textBox1.Location = new System.Drawing.Point(, );

            this.textBox1.Name = "textBox1";

            this.textBox1.Size = new System.Drawing.Size(, );

            this.textBox1.TabIndex = ;

            //

            // setTextUnsafeBtn

            //

            this.setTextUnsafeBtn.Location = new System.Drawing.Point(, );

            this.setTextUnsafeBtn.Name = "setTextUnsafeBtn";

            this.setTextUnsafeBtn.Size = new System.Drawing.Size(, );

            this.setTextUnsafeBtn.TabIndex = ;

            this.setTextUnsafeBtn.Text = "Unsafe Call";

            this.setTextUnsafeBtn.Click += new System.EventHandler(this.setTextUnsafeBtn_Click);

            //

            // setTextSafeBtn

            //

            this.setTextSafeBtn.Location = new System.Drawing.Point(, );

            this.setTextSafeBtn.Name = "setTextSafeBtn";

            this.setTextSafeBtn.Size = new System.Drawing.Size(, );

            this.setTextSafeBtn.TabIndex = ;

            this.setTextSafeBtn.Text = "Safe Call";

            this.setTextSafeBtn.Click += new System.EventHandler(this.setTextSafeBtn_Click);

            //

            // setTextBackgroundWorkerBtn

            //

            this.setTextBackgroundWorkerBtn.Location = new System.Drawing.Point(, );

            this.setTextBackgroundWorkerBtn.Name = "setTextBackgroundWorkerBtn";

            this.setTextBackgroundWorkerBtn.Size = new System.Drawing.Size(, );

            this.setTextBackgroundWorkerBtn.TabIndex = ;

            this.setTextBackgroundWorkerBtn.Text = "Safe BW Call";

            this.setTextBackgroundWorkerBtn.Click += new System.EventHandler(this.setTextBackgroundWorkerBtn_Click);

            //

            // backgroundWorker1

            //

            this.backgroundWorker1.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.backgroundWorker1_RunWorkerCompleted);

            //

            // Form1

            //

            this.ClientSize = new System.Drawing.Size(, );

            this.Controls.Add(this.setTextBackgroundWorkerBtn);

            this.Controls.Add(this.setTextSafeBtn);

            this.Controls.Add(this.setTextUnsafeBtn);

            this.Controls.Add(this.textBox1);

            this.Name = "Form1";

            this.Text = "Form1";

            this.Load += new System.EventHandler(this.Form1_Load);

            this.ResumeLayout(false);

            this.PerformLayout();

        }

        #endregion

    }

}