C#多线程

View Colorized第一种方法：

1. Query the control's InvokeRequired property.

2. If InvokeRequired returnstrue, call Invoke with a delegate that makes the actual call to the control.

3. If InvokeRequired returnsfalse, call the control directly.

第二种方法：使用BackgroundWorker

1. Create a method to do the work that you want done in the background thread. Do not call controls created by the main thread in this method.

2. Create a method to report the results of your background work after it finishes. You can call controls created by the main thread in this method.

3. Bind the method created in step 1 to the DoWork event of an instance of BackgroundWorker, and bind the method created in step 2 to the same instance’s RunWorkerCompleted event.

4. To start the background thread, call the RunWorkerAsync method of the BackgroundWorker instance.

using System;using System.ComponentModel;using System.Threading;using System.Windows.Forms;namespace CrossThreadDemo{    public class Form1 : Form    {        // This delegate enables asynchronous calls for setting        // the text property on a TextBox control.        delegate void SetTextCallback(string text);        // This thread is used to demonstrate both thread-safe and        // unsafe ways to call a Windows Forms control.        private Thread demoThread = null;        // This BackgroundWorker is used to demonstrate the         // preferred way of performing asynchronous operations.        private BackgroundWorker backgroundWorker1;        private TextBox textBox1;        private Button setTextUnsafeBtn;        private Button setTextSafeBtn;        private Button setTextBackgroundWorkerBtn;        private System.ComponentModel.IContainer components = null;        public Form1()        {            InitializeComponent();        }        protected override void Dispose(bool disposing)        {            if (disposing && (components != null))            {                components.Dispose();            }            base.Dispose(disposing);        }        // This event handler creates a thread that calls a         // Windows Forms control in an unsafe way.        private void setTextUnsafeBtn_Click(            object sender,             EventArgs e)        {            this.demoThread =                 new Thread(new ThreadStart(this.ThreadProcUnsafe));            this.demoThread.Start();        }        // This method is executed on the worker thread and makes        // an unsafe call on the TextBox control.        private void ThreadProcUnsafe()        {            this.textBox1.Text = "This text was set unsafely.";        }        // This event handler creates a thread that calls a         // Windows Forms control in a thread-safe way.        private void setTextSafeBtn_Click(            object sender,             EventArgs e)        {            this.demoThread =                 new Thread(new ThreadStart(this.ThreadProcSafe));            this.demoThread.Start();        }        // This method is executed on the worker thread and makes        // a thread-safe call on the TextBox control.        private void ThreadProcSafe()        {            this.SetText("This text was set safely.");        }        // This method demonstrates a pattern for making thread-safe        // calls on a Windows Forms control.         //        // If the calling thread is different from the thread that        // created the TextBox control, this method creates a        // SetTextCallback and calls itself asynchronously using the        // Invoke method.        //        // If the calling thread is the same as the thread that created        // the TextBox control, the Text property is set directly.         private void SetText(string text)        {            // InvokeRequired required compares the thread ID of the            // calling thread to the thread ID of the creating thread.            // If these threads are different, it returns true.            if (this.textBox1.InvokeRequired)            {                    SetTextCallback d = new SetTextCallback(SetText);                this.Invoke(d, new object[] { text });            }            else            {                this.textBox1.Text = text;            }        }        // This event handler starts the form's         // BackgroundWorker by calling RunWorkerAsync.        //        // The Text property of the TextBox control is set        // when the BackgroundWorker raises the RunWorkerCompleted        // event.        private void setTextBackgroundWorkerBtn_Click(            object sender,             EventArgs e)        {            this.backgroundWorker1.RunWorkerAsync();        }                // This event handler sets the Text property of the TextBox        // control. It is called on the thread that created the         // TextBox control, so the call is thread-safe.        //        // BackgroundWorker is the preferred way to perform asynchronous        // operations.        private void backgroundWorker1_RunWorkerCompleted(            object sender,             RunWorkerCompletedEventArgs e)        {            this.textBox1.Text =                 "This text was set safely by BackgroundWorker.";        }        #region Windows Form Designer generated code        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(12, 12);            this.textBox1.Name = "textBox1";            this.textBox1.Size = new System.Drawing.Size(240, 20);            this.textBox1.TabIndex = 0;            //             // setTextUnsafeBtn            //             this.setTextUnsafeBtn.Location = new System.Drawing.Point(15, 55);            this.setTextUnsafeBtn.Name = "setTextUnsafeBtn";            this.setTextUnsafeBtn.TabIndex = 1;            this.setTextUnsafeBtn.Text = "Unsafe Call";            this.setTextUnsafeBtn.Click += new System.EventHandler(this.setTextUnsafeBtn_Click);            //             // setTextSafeBtn            //             this.setTextSafeBtn.Location = new System.Drawing.Point(96, 55);            this.setTextSafeBtn.Name = "setTextSafeBtn";            this.setTextSafeBtn.TabIndex = 2;            this.setTextSafeBtn.Text = "Safe Call";            this.setTextSafeBtn.Click += new System.EventHandler(this.setTextSafeBtn_Click);            //             // setTextBackgroundWorkerBtn            //             this.setTextBackgroundWorkerBtn.Location = new System.Drawing.Point(177, 55);            this.setTextBackgroundWorkerBtn.Name = "setTextBackgroundWorkerBtn";            this.setTextBackgroundWorkerBtn.TabIndex = 3;            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(268, 96);            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.ResumeLayout(false);            this.PerformLayout();        }        #endregion        [STAThread]        static void Main()        {            Application.EnableVisualStyles();            Application.Run(new Form1());        }    }}