.NET BackgroundWorker的一般使用方式

代码如下：

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 TestBackGroundWorkerCompleteEvent
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            backgroundWorker.DoWork += OnDoWork;
            backgroundWorker.RunWorkerCompleted += OnRunWorkerCompleted;
        }        

        static BackgroundWorker backgroundWorker = new BackgroundWorker();

        private void OnDoWork(object sender, DoWorkEventArgs e)
        {
            Thread.Sleep();
            e.Result = "任务完成！";//传递结果
        }

        private void OnRunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            Action action = new Action(() =>
            {
                textBox.Text = e.Result.ToString();
            });

            this.textBox.BeginInvoke(action);  //在控件创建的线程更新控件，必须要执行上面的委托才行
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            backgroundWorker.RunWorkerAsync();
        }
    }
}

演示如下：