Answers

• JohnH GBMember ✭✭✭✭✭

  August 2019

  The items in your list view should be bound to items in an observable list. Then each switch in the view cell is bound to a property on the item. Your code simply iterates through everything in your observable list, setting that property to true.

  0
• Sreeee INMember ✭✭✭✭✭

  August 2019

  @JohnH Didn't get you. Can you show some code?

  0
• JohnH GBMember ✭✭✭✭✭

  August 2019

  @Sreeee said:
  @JohnH Didn't get you. Can you show some code?

  This is pretty basic Xamarin Forms and MVVM.
  In your example above, you already have a binding for the label Text in the viewcell view. You want another binding in the switch to a boolean property in the same item model.
  Then in your command or action, iterate through all the items and set that property to true.

  0
• ColeX Member, Xamarin Team Xamurai

  August 2019 Accepted Answer

  Model class

  public class Model : INotifyPropertyChanged 
  {
  
      private string _fullname;
      public string fullname {
          get {
              return _fullname;
          }
          set {
              if (value != this._fullname)
              {
                  this._fullname = value;
                  NotifyPropertyChanged();
              }
          }
      }
  
      private bool _toggled;
      public bool toggled
      {
          get
          {
              return _toggled;
          }
          set
          {
              if (value != this._toggled)
              {
                  this._toggled = value;
                  NotifyPropertyChanged();
              }
          }
      }
  
      public event PropertyChangedEventHandler PropertyChanged;
  
      private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
      {
          PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
      }
  
  }
  

  Populate the data , set it to ListView's itemsource.

  List<Model> list = new List<Model>();
  public Page3()
      {
          InitializeComponent();
  
          list.Add(new Model { fullname = "1", toggled = true });
          list.Add(new Model { fullname = "2", toggled = false });
          list.Add(new Model { fullname = "3", toggled = false });
          list.Add(new Model { fullname = "4", toggled = true });
          list.Add(new Model { fullname = "5", toggled = false });
  
          UserList.ItemsSource = list;
  
      }
  

  Button click to change the data

  private async void Button_Clicked(object sender, EventArgs e)
      {
          string option = await DisplayActionSheet("Title", null, null, new string[] { "Turn on", "Turn off" });
  
          if (option == "Turn on")
          {
              foreach (Model model in list)
              {
                  model.toggled = true;
              }
          }
          else if (option == "Turn off")
          {
              foreach (Model model in list)
              {
                  model.toggled = false;
              }
          }
      }
  

  

  In Addition , this the basic data binding , read the documentation https://docs.microsoft.com/en-us/xamarin/xamarin-forms/xaml/xaml-basics/data-binding-basics ,https://docs.microsoft.com/en-us/xamarin/xamarin-forms/xaml/xaml-basics/data-bindings-to-mvvm , next time you would implement by yourself instead asking here .

  6