[C#.NET] 如何 使用 BackgroundWorker 多執行緒 / 跨執行緒 存取UI

http://www.dotblogs.com.tw/yc421206/archive/2009/02/15/7174.aspx

如何使用BackgroundWorker控件

1.在winfrom裡拖拉一個BackgroundWorker控件至from裡

 

 

2.使用RunWorkerAsync方法，將會觸動DoWork事件

this.backgroundWorker1.RunWorkerAsync(count);

 

 

 

3.在DoWork事件的方法中調用需要執行的方法

4.在方法中傳遞BackgroundWorker參數

5.允許BackgroundWorker報告進度

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

{

//4.在方法中傳遞BackgroundWorker參數

RunSample04(sender as BackgroundWorker);

//5.允許BackgroundWorker報告進度

this.backgroundWorker1.WorkerReportsProgress = true;

this.progressBar1.Maximum = count;

}

 

 

6.執行ReportProgress方法，觸發ProgressChanged事件

private void RunSample04(BackgroundWorker myWork)

{

myStr = "";

for (int i = 1; i <= count; i++)

{

try

{

//6.執行ReportProgress方法，觸發ProgressChanged事件

myWork.ReportProgress(i);

myStr = i.ToString();

}

catch (Exception ex)

{

Console.WriteLine(ex.Message);

}

Thread.Sleep(1);

Application.DoEvents();

}

}

 

 

7.ProgressChanged事件顯示，回傳執行結果

//在ProgressChanged事件的方法中顯示進度

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)

{

try

{

//7.回傳執行結果

this.textBox2.Text = myStr;

this.progressBar1.Value = e.ProgressPercentage;

Thread.Sleep(1);

}

catch (Exception ex)

{

Console.WriteLine(ex.Message);

}

}

 

 

8.RunWorkerCompleted事件顯示，執行完成結果

//在RunWorkerCompleted事件的方法中顯示被執行方法的結果

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)

{

//if (e.Error != null)

//{

//    MessageBox.Show(e.Error.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);

//    return;

//}

//else if (e.Cancelled)

//{

//    MessageBox.Show("取消操作！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

//    return;

//}

//else

//{

//    MessageBox.Show("操作成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

//}

}

 

執行結果：