winform BackgroundWorker组件操作

 

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.Windows.Forms;

namespace BackgroundWorkTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 开始运行按钮
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnStart_Click(object sender, EventArgs e)
        {
            if (backgroundWorker1.IsBusy)
            {
                MessageBox.Show("正在运行线程");
                return;
            }

            backgroundWorker1.RunWorkerAsync(1000);
        }

        /// <summary>
        /// 后台组件工作中运行的代码
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e">e.Argument传递的数值</param>
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            int n = 0;
            int sum = 0;
            //获取异步操作的数值
            if (e.Argument != null)
            {
                n = (int)e.Argument;
            }

            for (int i = 0; i < n; i++)
            {
                //是否取消后台操作
                if (backgroundWorker1.CancellationPending)
                {
                    e.Cancel = true;
                    return;
                }
                sum += i;
                Thread.Sleep(10);
                //通过计算,传递值为100.比如i=1000，i / 10 = 100;
                backgroundWorker1.ReportProgress(i / 10, "当前i的值为" + Convert.ToString(i));
            }
            //异步操作结果的值
            e.Result = sum;
        }

        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            //注意value数值不能大于100
            progressBar1.Value = e.ProgressPercentage;
            label1.Text = e.UserState.ToString();
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            //异步操作期间是否出错
            if (!(e.Error == null))
            {
                MessageBox.Show(e.Error.Message);
                return;
            }

            //异步操作期间是否取消
            if (e.Cancelled)
            {
                progressBar1.Value = 0;
                label1.Text = "";
                MessageBox.Show("取消线程的执行");
                return;
            }

            label1.Text = "计算结果:" + e.Result.ToString();
         //   this.progressBar1.Value = 100;
        }

        /// <summary>
        /// 取消按钮
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnCancel_Click(object sender, EventArgs e)
        {
            if (!backgroundWorker1.IsBusy) return;

            //取消后台操作
            backgroundWorker1.CancelAsync();
           
        }
    }
}