長時間操作時禁用按鈕

Question

長時間操作時，我想禁用按鈕並清除文本塊。

在按鈕點擊畫的屏幕使按鍵永不明顯禁用

private bool btnEnabled = true; 
public bool BtnEnabled 
{ 
    get { return btnEnabled; } 
    set 
    { 
     if (value == btnEnabled) 
      return; 
     btnEnabled = value; 
     NotifyPropertyChanged("BtnEnabled"); 
    } 
} 
private string results = "start"; 
public string Results 
{ 
    get { return results; } 
    set 
    { 
     if (value == results) 
      return; 
     results = value; 
     NotifyPropertyChanged("Results"); 
    } 
} 

private void btn_Click(object sender, RoutedEventArgs e) 
{ 
    BtnEnabled = false; 
    Results = string.Empty; 
    // whould like to displany wait spinner 
    LongProcess(); 
    BtnEnabled = true; 
} 
private void LongProcess() 
{ 
    //database query 
    System.Threading.Thread.Sleep(10000); 
    Results = "this is the results"; 
} 

如何獲得的按鈕長事件期間禁用前的事件完全處理的？

問題我有是用戶感到沮喪，並開始點擊和這些點擊都在隊列中並得到處理。

Answer 1

這是我結束了

private async void btn_Click(object sender, RoutedEventArgs e) 
{ 

    BtnEnabled = false; 
    Results = string.Empty; 
    // whould like to displany wait spinner 
    //LongProcess(); 
    cts = new CancellationTokenSource(); 
    try 
    { 
     //cts.Cancel(); just for test 
     string result = await WaitAsynchronouslyAsync(cts.Token); 
     //string result = await WaitSynchronously(); 

     BtnEnabled = true; 
     Results = result; 
    } 
    catch (OperationCanceledException) 
    { 
     Results = "Operation canceled"; // this is not called 
    } 
    cts = null; 
} 
// The following method runs asynchronously. The UI thread is not 
// blocked during the delay. You can move or resize the Form1 window 
// while Task.Delay is running. 
public async Task<string> WaitAsynchronouslyAsync(CancellationToken ct) 
{ 
    //DataBaseQuery(); // this just runs async 
    //SqlCommand cmd = new SqlCommand(); 
    //await cmd.ExecuteScalarAsync(ct); 
    await Task.Delay(10000); 
    return "Finished"; 
} 

Answer 2

爲了回答您的具體問題，你可以使用這樣的事情，使UI過程中的消息（在設置按鈕禁用）：

Application.Current.Dispatcher.Invoke(
      DispatcherPriority.Background, 
      new Action(delegate { }) 
      ); 

還是較爲齊全：

public void DoEvents() 
{ 
    DispatcherFrame frame = new DispatcherFrame(); 
    Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, 
     new DispatcherOperationCallback(ExitFrame), frame); 
    Dispatcher.PushFrame(frame); 
} 

public object ExitFrame(object f) 
{ 
    ((DispatcherFrame)f).Continue = false; 
    return null; 
} 

再次，這不建議（它相當於Winforms上使用Application.DoEvents()，它有許多警告，應該像瘟疫一樣避免，除非你知道你在做什麼）。長時間的密集操作不應該在UI線程上完成，或者如果CPU密集度不高，則可以使用async/await。