学步园

在C#.net窗体编程中，非主线程调用该UI界面的时候往往会出现一些界面无响应或者假死的情况，我们可以用Backgroundworker很好的解决这一个问题。

第一步，我们先建立一个Windows应用程序，取名XXX

第二步，我们在左侧工具箱中找到组件下面的BackgroundWorker组件，拖至Form中，为了让大家很好的体验到Background的作用，我们拖放两个Backgroundworker组件到Form中，分别为backgroudworker1和backgroundworker2

第三步，分别选择这两个组件的属性WorkReportsProgress和WorkerSupportsCancellation属性设置为true,先做个小小的解释，WorkReportsProgress：backgroundworker组件的DoWork事件触发的时候，会想backgroundworker组件报告DoWork事件中的执行情况，这样，我们就可以对UI进行相应的抄作，如果暂时看不懂，没关系，可能是我解释得太差了，看了下面的代码大家一定会明白...

第四步，确认第三不工作已经完成的情况下，我们在界面上拖放两个Button，分别为btn1,btn2,以及两个processbar，分别为processbar1,processbar2

第四步，backgroundworker1 组件有三个事件，分别为

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)<br /> {</p> <p> }</p> <p> private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)<br /> {</p> <p> }</p> <p> private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)<br /> {</p> <p> }

现在我们来让这两个进度条走起来

using System;<br /> using System.Collections.Generic;<br /> using System.ComponentModel;<br /> using System.Data;<br /> using System.Drawing;<br /> using System.Linq;<br /> using System.Text;<br /> using System.Windows.Forms;</p> <p>namespace BackGroundWork<br /> {<br /> public partial class Form1 : Form<br /> {<br /> public Form1()<br /> {<br /> InitializeComponent();<br /> }</p> <p> private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)<br /> {<br /> for (int i = 1; i <= 65; i++)<br /> {<br /> this.backgroundWorker1.ReportProgress(i);<br /> System.Threading.Thread.Sleep(200);<br /> }<br /> }</p> <p> private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)<br /> {<br /> int m=e.ProgressPercentage*100/65;<br /> this.progressBar1.Value = m;<br /> this.label1.Text = m + "%";<br /> }</p> <p> private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)<br /> {<br /> this.button1.Enabled = true;<br /> this.progressBar1.Value = 0;<br /> MessageBox.Show("BackgroundWorker1 任务完成");<br /> }</p> <p> private void button1_Click(object sender, EventArgs e)<br /> {<br /> this.button1.Enabled = false;<br /> this.backgroundWorker1.RunWorkerAsync();<br /> }</p> <p> private void button2_Click(object sender, EventArgs e)<br /> {<br /> this.button2.Enabled = false;<br /> this.backgroundWorker2.RunWorkerAsync();<br /> }</p> <p> private void backgroundWorker2_DoWork(object sender, DoWorkEventArgs e)<br /> {<br /> for (int i = 1; i <= 30; i++)<br /> {<br /> this.backgroundWorker2.ReportProgress(i);<br /> System.Threading.Thread.Sleep(500);<br /> }<br /> }</p> <p> private void backgroundWorker2_ProgressChanged(object sender, ProgressChangedEventArgs e)<br /> {<br /> int m = e.ProgressPercentage * 100 / 65;<br /> this.progressBar2.Value = m;<br /> this.label2.Text = m + "%";<br /> }</p> <p> private void backgroundWorker2_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)<br /> {<br /> this.button2.Enabled = true;<br /> this.progressBar2.Value = 0;<br /> MessageBox.Show("BackgroundWorker2 任务完成");<br /> }</p> <p> private void button3_Click(object sender, EventArgs e)<br /> {<br /> this.backgroundWorker1.Dispose();<br /> this.progressBar1.Value = 0;<br /> this.label1.Hide();<br /> }<br /> }<br /> }<br />