using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;namespace WindowsFormsApplication1
{public partial class Form1 : Form{public Form1(){InitializeComponent();           }private void button1_Click(object sender, EventArgs e){Thread t = new Thread(ModifyLabelText);t.Start();}/// <summary>/// 定义委托/// </summary>private delegate void InvokeDelegate();/// <summary>/// this.label1.InvokeRequired就是问问我们要不要使用代理执行ModifyLabelText方法/// </summary>private void ModifyLabelText(){//使用Invoke代理的方式调用ModifyLabelText方法if (this.label1.InvokeRequired){InvokeDelegate invokeDelegate=new InvokeDelegate(ModifyLabelText);this.Invoke(invokeDelegate);                }else{this.label1.Text = "我已经跨线程修改了Label的值";}}}
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;namespace WindowsFormsApplication1
{public partial class Form1 : Form{public Form1(){InitializeComponent();           }private void button1_Click(object sender, EventArgs e){Thread t = new Thread(ModifyLabelText);t.Start();}/// <summary>/// 定义委托/// </summary>private delegate void InvokeDelegate();/// <summary>/// this.label1.InvokeRequired就是问问我们要不要使用代理执行ModifyLabelText方法/// </summary>private void ModifyLabelText(){//使用BeginInvoke代理的方式调用ModifyLabelText方法if (this.label1.InvokeRequired){InvokeDelegate invokeDelegate=new InvokeDelegate(ModifyLabelText);this.BeginInvoke(invokeDelegate);                }else{this.label1.Text = "我已经跨线程修改了Label的值";}}}
}

您必须非常小心，确保在 DoWork 事件处理程序中不操作任何用户界面对象（否则仍会停止响应）。而应该通过 ProgressChanged和 RunWorkerCompleted 事件与用户界面进行通信。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;namespace WorkerBackgrounderExmple
{public partial class Form1 : Form{public Form1(){InitializeComponent();}private static int MaxRecords = 100;private void btnStart_Click(object sender, EventArgs e){if (backgroundWorker1.IsBusy){return;}this.listView1.Items.Clear();this.backgroundWorker1.RunWorkerAsync(MaxRecords);this.btnStart.Enabled= false;this.btnCancel.Enabled= true;}private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e){try{e.Result = this.RetrieveData(this.backgroundWorker1, e);}catch (Exception ex){MessageBox.Show(ex.Message);throw;}}private int RetrieveData(BackgroundWorker worker, DoWorkEventArgs e){int maxRecords=(int)e.Argument;int percent=0;for (int i = 1; i <=maxRecords; i++){if (worker.CancellationPending){return i;}percent=(int)(((double)i/(double)maxRecords)*100);worker.ReportProgress(percent, new KeyValuePair<int, string>(i, Guid.NewGuid().ToString()));Thread.Sleep(100);}return maxRecords;}private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e){KeyValuePair<int, string> record = (KeyValuePair<int, string>)e.UserState;this.label1.Text = string.Format("There are {0} records retrieved!", record.Key);this.progressBar1.Value = e.ProgressPercentage;this.listView1.Items.Add(record.Value);}private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e){try{this.label1.Text = string.Format("Total records: {0}", e.Result);this.btnStart.Enabled = true;this.btnCancel.Enabled = false;}catch (TargetInvocationException ex){MessageBox.Show(ex.InnerException.GetType().ToString());}}private void btnCancel_Click(object sender, EventArgs e){this.backgroundWorker1.CancelAsync();}}
}