在c中使用進度條＃

Question

我想在我的c＃應用程序中顯示一個進度條。有一個函數，我正在調用按鈕單擊在我的應用程序中，這是耗時的，不可能確定它需要多少時間以完成整個過程，因爲我正在從Excel表格讀取數據並存儲到數據庫和所有東西。當我點擊按鈕進度條應顯示正確的狀態，當整個過程完成時，我想顯示一條消息的「成功完成」。

AlertForm alert; 
    private void btnImport_Click(object sender, EventArgs e) 
    { 
if (backgroundWorker1.IsBusy != true) 
        { 
         // create a new instance of the alert form 
         alert = new AlertForm(); 
         // event handler for the Cancel button in AlertForm 
         alert.Canceled += new EventHandler<EventArgs>(buttonCancel_Click); 
         alert.Show(); 



         backgroundWorker1.RunWorkerAsync(); 

                StartConversion(txtPath.Text.Trim(), Path.GetFileName(txtPath.Text.Trim())); 

        } 
} 

#region Progress bar EVENTS 

    private void buttonStart_Click(object sender, EventArgs e) 
    { 
     if (backgroundWorker1.IsBusy != true) 
     { 
      // create a new instance of the alert form 
      alert = new AlertForm(); 
      // event handler for the Cancel button in AlertForm 
      alert.Canceled += new EventHandler<EventArgs>(buttonCancel_Click); 
      alert.Show(); 
      // Start the asynchronous operation. 
      backgroundWorker1.RunWorkerAsync(); 
     } 
    } 

    // This event handler cancels the backgroundworker, fired from Cancel button in AlertForm. 
    private void buttonCancel_Click(object sender, EventArgs e) 
    { 
     if (backgroundWorker1.WorkerSupportsCancellation == true) 
     { 
      // Cancel the asynchronous operation. 
      backgroundWorker1.CancelAsync(); 
      // Close the AlertForm 
      alert.Close(); 
     } 
    } 

    // This event handler is where the time-consuming work is done. 
    private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
    { 
     BackgroundWorker worker = sender as BackgroundWorker; 

     for (int i = 1; i <= 10; i++) 
     { 
      if (worker.CancellationPending == true) 
      { 
       e.Cancel = true; 
       break; 
      } 
      else 
      { 
       // Perform a time consuming operation and report progress. 
       worker.ReportProgress(i * 10); 
       System.Threading.Thread.Sleep(500); 
      } 
     } 
    } 

    // This event handler updates the progress. 
    private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) 
    { 
     // Show the progress in main form (GUI) 
     labelResult.Text = (e.ProgressPercentage.ToString() + "%"); 
     // Pass the progress to AlertForm label and progressbar 
     alert.Message = "In progress, please wait... " + e.ProgressPercentage.ToString() + "%"; 
     alert.ProgressValue = e.ProgressPercentage; 


    } 

    // This event handler deals with the results of the background operation. 
    private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
    { 
     if (e.Cancelled == true) 
     { 
      labelResult.Text = "Canceled!"; 
     } 
     else if (e.Error != null) 
     { 
      labelResult.Text = "Error: " + e.Error.Message; 
     } 
     else 
     { 
      labelResult.Text = "Done!"; 
     } 
     // Close the AlertForm 
     alert.Close(); 
    } 

    #endregion 

檢測AlertForm Ia的我的應用程序的另一種形式，其用於顯示進度條 StartConversion（）方法是調用另一個方法，其是本其actualy執行耗時的任務的一類內的方法。

我該如何實現這個任務？ 請幫我....

Answer 1

這通常是使用BackgroundWorker

它運行在一個單獨的線程，並提供工具來實現您的兩個要求（更新進度信息和做某事完成的。當操作完成）。您只需創建BackgroundWorker的實例並將其WorkerReportsProgress-屬性設置爲true。

然後只需認購event及其對應您的需求：

1. DoWork - 執行實際的長期運行的任務
2. ProgressChanged - 更新Progressinformation接枝（eG進度值）
3. RunWorkerCompleted - 顯示您的成功 - 消息

最後調用RunWorkerAsync -M方法，你就完成了。

示例代碼

var demoWorker = new BackgroundWorker { WorkerReportsProgress = true }; 
demoWorker.DoWork += (sender, args) => 
      { 
       var worker = sender as BackgroundWorker; 

       if (sender == null) throw new Exception("Not a BackgroundWorker!"); 

       foreach (var VARIABLE in COLLECTION) 
       { 
        // do your work 

        worker.ReportProgress(progressPercentage); // invokes the workers ProgressChanged-event 
       } 
      } 

demoWorker.ProgressChanged += (sender, args) => 
      { 
       this.progressBar.Value = args.ProgressPercentage; 
      };  

demoWorker.RunWorkerCompleted += (sender, args) => 
      { 
       // invoked when DoWork's eventhandler terminates 
       // show message 
      }; 

demoWorker.RunWorkerAsync(); // Invokes the workers DoWork-event 

Answer 2

你應該用backgroundworker工作。

圖片以下情形：

您有一個Excel，大約有1000行進程文件。對於進度條，您可以假定10行是百分比。

每隔一段時間在後臺工作中，您讓它與主線程進行通信，說明處理了多少個百分比。

BackgroundWorker的具有可用於填充你的進度飄飛的事件：

例如：

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
    { 
     BackgroundWorker worker = sender as BackgroundWorker; 

     var base = 100; 
     var counter = ExcelRows.Count; 
     var progressCounter = 0; 
     for (int i = 1; i <= ExcelRows.Count; i++) 
     { 
      if (worker.CancellationPending == true) 
      { 
       e.Cancel = true; 
       break; 
      } 
      else 
      { 
       // Perform a time consuming operation and report progress. 
       //perform you action 
       MyRow.Save(); 

       //report to the Progressbar 
       if(i % counter == 0) 
        worker.ReportProgress(progressCounter++); 
      } 
     } 
    } 

    // This event handler updates the progress. 
    private void backgroundWorker1_ProgressChanged(object sender,   ProgressChangedEventArgs e) 
    { 
     MyProgress.Value = string.Format("{0}/100 %",e.ProgressPercentage); 
    }