表單不會在Backgroundworker中顯示爲對話框？

Question

窗體不顯示爲backgroundworker中的對話框？

這裏是我的代碼：

//From Form1 
     private void backgroundWorkerResult_DoWork(object sender, DoWorkEventArgs e) 
    { 
     //do something here 

     backgroundWorkerResult.ReportProgress(100); 

     frmMessageBox frmMsgBox = new frmMessageBox(); 
     frmMsgBox.ShowDialog(); 
    } 

即使我已經表明frmMsgBox作爲一個對話框我還可以單擊應該是沒有Form1？如何解決這個問題？

Answer 1

我創建了一個簡單的代碼示例，您可以使用它來了解後臺工作程序的工作方式。將代碼複製到測試窗體並添加以下控件

1. 標籤控制 - 將它命名爲「lblStatus」
2. 進度控制 - 它應該被命名爲progressBar1。
3. 添加名爲'btnStartAsyncOperation'和'btnCancel'的2個按鈕和鏈接其點擊事件。

基本上你應該顯示在結果RunWorkerCompleted事件

public partial class Form1 : Form 
    { 
     BackgroundWorker backgroundWorker; 

     public Form1() 
     { 
      InitializeComponent(); 
      backgroundWorker = new BackgroundWorker {WorkerReportsProgress = true, WorkerSupportsCancellation = true}; 

      backgroundWorker.DoWork += new DoWorkEventHandler(BackgroundWorker_DoWork); 
      backgroundWorker.ProgressChanged += new ProgressChangedEventHandler(BackgroundWorker_ProgressChanged); 
      backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BackgroundWorker_RunWorkerCompleted); 

     } 

     void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
     { 
      if (e.Cancelled) 
       lblStatus.Text = "Task Cancelled."; 
      else if (e.Error != null) 
       lblStatus.Text = "Error - " + e.Error.Message; 
      else 
       lblStatus.Text = "Task Completed..."; 

      btnStartAsyncOperation.Enabled = true; 
      btnCancel.Enabled = false; 
     } 

     void BackgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e) 
     { 
      progressBar1.Value = e.ProgressPercentage; 
      lblStatus.Text = "Processing......" + progressBar1.Value.ToString() + "%"; 
     } 

     void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e) 
     { 
      for (int i = 0; i < 100; i++) 
      { 
       System.Threading.Thread.Sleep(100); 
       backgroundWorker.ReportProgress(i); 
       if (backgroundWorker.CancellationPending) 
       { 
        e.Cancel = true; 
        backgroundWorker.ReportProgress(0); 
        return; 
       } 
      } 
      backgroundWorker.ReportProgress(100); 
     } 

     private void btnStartAsyncOperation_Click(object sender, EventArgs e) 
     { 
      btnStartAsyncOperation.Enabled = false; 
      btnCancel.Enabled = true; 
      backgroundWorker.RunWorkerAsync(); 
     } 

     private void btnCancel_Click(object sender, EventArgs e) 
     { 
      if (backgroundWorker.IsBusy) 
      { 
       backgroundWorker.CancelAsync(); 
      } 
     } 
    } 

由OP

市價修改意見在DoWork的情況下，設定你的字符串如下

e.Result = "Your String"; 

a第二在RunWorkerCompleted事件

string muResult = Convert.ToString(e.Result); 

注： e.Result是一個對象，所以你甚至可以用它的多個屬性中設置自定義類。