Xamarin表单更新listView itemSource

Question

好吧,我有一个ListView具有List<Filiale>as 的对象,ItemSource我想ItemSource在对象列表更改时刷新.ListView有一个个性化的ItemTemplate 现在我已经这样做了:

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;
}

正如您在TextChanged方法中看到的,我为前一个方法分配了一个新列表,但视图中没有任何更改.在ViewCell我创建的内容中,我使用了分配标签的文本字段SetBinding

Answer 1

您可以将ListView的ItemsSource设置为null,然后再将其重新设置为表重新加载. http://forums.xamarin.com/discussion/18868/tableview-reloaddata-equivalent-for-listview

Answer 2

好的，这是我解决问题的方法，首先，我创建了一个“包装器”，该包装器INotifyPropertyChanged为像这样作为ItemSource的列表实现了：

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();
        }

然后在NearMe类中：

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 ();
            }