在C#.net窗體程式設計中，非主執行緒呼叫該UI介面的時候往往會出現一些介面無響應或者假死的情況，我們可以用Backgroundworker很好的解決這一個問題。

第一步，我們先建立一個Windows應用程式，取名XXX

第二步，我們在左側工具箱中找到元件下面的BackgroundWorker元件，拖至Form中，為了讓大家很好的體驗到Background的作用，我們拖放兩個Backgroundworker元件到Form中，分別為backgroudworker1和backgroundworker2

第三步，分別選擇這兩個元件的屬性WorkReportsProgress和WorkerSupportsCancellation屬性設定為true,先做個小小的解釋，WorkReportsProgress：backgroundworker元件的DoWork事件觸發的時候，會想backgroundworker元件報告DoWork事件中的執行情況，這樣，我們就可以對UI進行相應的抄作，如果暫時看不懂，沒關係，可能是我解釋得太差了，看了下面的程式碼大家一定會明白...

第四步，確認第三不工作已經完成的情況下，我們在介面上拖放兩個Button，分別為btn1,btn2,以及兩個processbar，分別為processbar1,processbar2

第四步，backgroundworker1 元件有三個事件，分別為

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { } private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) { } private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { }

現在我們來讓這兩個進度條走起來

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