Xamarin form update listView itemSource

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Ok I have a ListView object which have a List<Filiale> as ItemSource and I'd like to refresh the ItemSource whenever the list of object change. The ListView has a personalized ItemTemplate For now I have done this:

public NearMe ()
{
    list=jM.ReadData ();
    listView.ItemsSource = list;
    listView.ItemTemplate = new DataTemplate(typeof(FilialeCell));
    searchBar = new SearchBar {
        Placeholder="Search"
    };
    searchBar.TextChanged += (sender, e) => {
        TextChanged(searchBar.Text);
    };
    var stack = new StackLayout { Spacing = 0 };
    stack.Children.Add (searchBar);
    stack.Children.Add (listView);
    Content = stack;
}

public void TextChanged(String text){
        //DOSOMETHING
        list=newList;
}

As you can see in the TextChanged method I assign a new list to the previous one but there are no changes in the view. In the ViewCell that I created I assign the Text field of the Labels with the SetBinding

You can set the ItemsSource of the ListView to null, and then set it back again, that does a table reload. http://forums.xamarin.com/discussion/18868/tableview-reloaddata-equivalent-for-listview

Update ListView XAML Programmatically — Xamarin Community , I am trying to update a ListView's ViewCell using C# code. Basically I want to Iterate through the listview and change the visibility of certain� Hi I'm pretty new in the Xamarin Forms world and I'm trying to have the listView that I created refresh its content when the itemSource change. This site uses cookies for analytics, personalized content and ads.

Ok here is how I solved the problem, first of all I created a "wrapper" that implement INotifyPropertyChanged for the list that I was taking as ItemSource like this :

public class Wrapper : INotifyPropertyChanged
    {
        List<Filiale> list;
        JsonManager jM = new JsonManager ();//retrieve the list

        public event PropertyChangedEventHandler PropertyChanged;
        public NearMeViewModel ()
        {
            list = (jM.ReadData ()).OrderBy (x => x.distanza).ToList();//initialize the list
        }

        public List<Filiale> List{ //Property that will be used to get and set the item
            get{ return list; }

            set{ 
                list = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, 
                        new PropertyChangedEventArgs("List"));// Throw!!
                }
            }
        }

        public void Reinitialize(){ // mymethod
            List = (jM.ReadData ()).OrderBy (x => x.distanza).ToList();
        }

Then in the NearMe class:

Wrapper nearMeVM = new Wrapper();
public NearMe ()
        {

            Binding myBinding = new Binding("List");
            myBinding.Source = nearMeVM;
            myBinding.Path ="List";
            myBinding.Mode = BindingMode.TwoWay;
            listView.SetBinding (ListView.ItemsSourceProperty, myBinding); 
            listView.ItemTemplate = new DataTemplate(typeof(FilialeCell));
            searchBar = new SearchBar {
                Placeholder="Search"
            };
            searchBar.TextChanged += (sender, e) => {
                TextChanged(searchBar.Text);
            };
            var stack = new StackLayout { Spacing = 0 };
            stack.Children.Add (searchBar);
            stack.Children.Add (listView);
            Content = stack;
        }
public void TextChanged(String text){
            if (!String.IsNullOrEmpty (text)) {
                text = text [0].ToString ().ToUpper () + text.Substring (1);
                var filterSedi = nearMeVM.List.Where (filiale => filiale.nome.Contains (text));
                var newList = filterSedi.ToList ();
                nearMeVM.List = newList.OrderBy (x => x.distanza).ToList ();
            } else {
                nearMeVM.Reinitialize ();
            }

ListView Data Sources, Forms ListView with data, and how to use data binding with a Because ItemsSource has been sent to an array, the content will not update as� A Xamarin.Forms ListView is used for displaying lists of data. This article explains how to populate a ListView with data and how to bind data to the selected item. ItemsSource. A ListView is populated with data using the ItemsSource property, which can accept any collection implementing IEnumerable.

You can define a base view model and inherit it from INotifyPropertyChanged

public abstract class BaseViewModel : INotifyPropertyChanged
    {
        protected bool ChangeAndNotify<T>(ref T property, T value, [CallerMemberName] string propertyName = "")
        {
            if (!EqualityComparer<T>.Default.Equals(property, value))
            {
                property = value;
                NotifyPropertyChanged(propertyName);
                return true;
            }


            return false;
        }


        protected void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

then in your viewmodel (Ex. JM) will be inherit from BaseViewModel and can create ObservableCollection<YOURLISTCLASS> List

Also your fields in ViewModel (Ex. JM) should implement like following:

public const string FirstNamePropertyName = "FirstName";
private string firstName = string.Empty;
public string FirstName 
{
    get { return firstName; }
    set { this.ChangeAndNotify(ref this.firstName, value, FirstNamePropertyName); }
} 

Hope this helps.

Updating the Items Displayed of a listView in Xamarin.Forms , Using the Code. First, you have your list in your .xaml file: Hide Shrink Copy Code. <ListView x:Name="ItemsListView" ItemsSource="{Binding� Xamarin Forms ListView Binding to Child Object List in an Observable collection. 1. Xamarin Forms Collection view ItemsSource Binding not updating the UI. 0.

Change List to ObservableCollection and implement INotifyPropertyChanged to have changes reflect in your ListView.

Refresh ListView in Xamarin Forms, Learn how to refresh a ListView in Xamarin Forms to add or remove items from a list.Duration: 5:37 Posted: Oct 30, 2016 Create a Xamarin.Forms ListView in XAML. Populate the ListView with data. Respond to ListView items being selected. Customize the ListView cell appearance.

Just convert your System.Collections.Generic.List to a System.Collections.ObjectModel.ObservableCollection before binding it to the ListView.

Xamarin Forms Pull To Refresh With ListView, The Xamarin Forms ListView control has the ability to allow the user to pull down from the top of the ListView to trigger a refresh command. <ListView ItemsSource="{Binding MyList}" IsPullToRefreshEnabled="True"� If you create a new observable collection, the code behind will correctly point to the new one but the listView will continue bind to the old one. Finally, to make it work with Android 7, following this link, you need to add a reference to System.ObjectModel in the Android project - not in the library project.

I'm trying to make a listview in xamarin show data from a restapi but have the option to filter the list or sort it based upon last name. I've set the bindingcontext equal to the apiviewmodel which works. But I want to set the itemssource to a list which can be manipulated later instead of the binding context. Here is the code that works: Xaml:

ListViews are a popular way to display data in a mobile app. However, they're difficult to visualize without real data. To use design time data with them, you have to create a design time array to use as an ItemsSource. The XAML Previewer displays what is in that array in your ListView at design time.

Bindable layouts were introduced way back in Xamarin.Forms 3.5 and is a hidden gem that you need to know about. Bindable layouts takes any Xamarin.Forms layout and allows you to repeat content using ItemsSource, ItemTemplate, and even ItemTemplateSelector. This will feel very familiar if you have used ListView or CollectionView before.

Comments
  • you can inherit your viewmodel (if you're using) from INotifyPropertyChanged
  • Check out this link which may help you..
  • Finally I have understand this, Thanks!
  • Who should implement INotifyPropertyChanged ?
  • You should do that. Extend you item model with it: msdn.microsoft.com/en-us/library/ms743695(v=vs.110).aspx
  • What do you mean by that?
  • It was referred to the You should do that, it seemed like you misread my question.
  • I modify all the list not a single object, is there a way to do this instead of let each field of Filiale fire propertychanged?