如何將開關值設置爲開/關並防止在Xamarin表格中切換方法調用

Question

在PCL項目中，使用Xamarin格式，我將開關位置設置爲開/關，這將調用切換事件。在切換切換事件中有確認提醒，如果用戶選擇「否」，它將再次將切換設置爲先前狀態。 問題是，如果按「否」，切換的方法會被再次調用。我想阻止方法調用。

Switch switcher = new Switch 
{ 
    HorizontalOptions = LayoutOptions.Center, 
    VerticalOptions = LayoutOptions.CenterAndExpand 
}; 
switcher.Toggled += switcher_Toggled; 

void switcher_Toggled(object sender, ToggledEventArgs e) 
    { 
     Device.BeginInvokeOnMainThread(async() => 
     { 

      bool alert; 

      if (this._isConnectionStatusOpen == true) 
      { 
       alert = await DisplayAlert("Close ", "Are you sure you want to close connection?", "Yes", "No"); 
      } 
      else 
      { 
       alert = await DisplayAlert("Open", "Are you sure you want to Open connection?", "Yes", "No"); 

      } 

      if (alert != true) 
      { 
       Switch thisSender = (Switch)sender; 
       thisSender.IsToggled = !thisSender.IsToggled; 
      } 
     }); 
    } 

有沒有簡單的方法來實現它？

Answer 1

只需添加NoLoop布爾。

private bool NoLoop { get; set; } 

void switcher_Toggled(object sender, ToggledEventArgs e) 
     { 
      Device.BeginInvokeOnMainThread(async() => 
      { 
       if (NoLoop) 
       { 
        NoLoop = false; 
        return; 
       } 
       bool alert; 

       if (this._isConnectionStatusOpen == true) 
       { 
        alert = await DisplayAlert("Close ", "Are you sure you want to close connection?", "Yes", "No"); 
       } 
       else 
       { 
        alert = await DisplayAlert("Open", "Are you sure you want to Open connection?", "Yes", "No"); 

       } 

       if (alert != true) 
       { 
        NoLoop = true; 
        Switch thisSender = (Switch)sender; 
        thisSender.IsToggled = !thisSender.IsToggled; 

       } 
      }); 
     }