Clever Geek Handbook

Refreshing or updating a list in a Windows Phone 8.1 app using C # and XAML

I need to update ListView

on upgrade ItemsSource

. I have declared myListView

as ListView

in a XAML file and assigned myList

as source to items in C # code with the following piece of code:

myListView.ItemsSource = myList;

Now, my question is, how can I update myListView

?

+3


source to share


5 answers


What do you mean by updating? If you want your UI to be updated, your myList must be of type ObservableCollection and your class must implement the INotifyPropertyChanged interface.

Check this message



https://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged%28v=vs.110%29.aspx

+3


source


You need to use and ObservableCollection

public ObservableCollection<string> MyList { get; set; }


After setting the observable collection as your ItemsSource, every change to the collection will be automatically reflected in your list.

+2


source


The great thing is that it only works with System.Collections.ObjectModel.ObservableCollection

and then set the collection to ListView.ItemsSource

.

0


source


try it

  if (ListView.Items.Count > 0)
  {
     ListView.ItemsSource = null;
  }
  listItem.Clear();

Simply assigning new list view objects does not clear the data. You need to clear the ItemSource and also clear the list array used to bind the list view

0


source


I created a test app - krayknot to test this scenario and here is the code:

Include INotifyPropertyChanged

public sealed partial class PivotPage : Page, INotifyPropertyChanged

create event handler

public event PropertyChangedEventHandler PropertyChanged;

Create ObservableCollection

ObservableCollection<Feeds> oc = new ObservableCollection<Feeds>();

and here is the method,

private async void BindFeeds(string URL)
        {
            progressRing.IsActive = true;

            var uri = new Uri(URL);
            var httpClient = new HttpClient();

            // Always catch network exceptions for async methods
            httpClient.DefaultRequestHeaders.Add("Cache-Control", "no-cache");
            var result = await httpClient.GetAsync(uri);

            var xmlStream = await result.Content.ReadAsStreamAsync();
            XDocument loadedData = XDocument.Load(xmlStream);

            foreach (var data in loadedData.Descendants("Table"))
            {


                try
                {
                    oc.Add(new Feeds
                    {
                        BlogId = data.Element("Blogs_CID").Value.ToString(),
                        Description = data.Element("Blogs_BriefDescription").Value.ToString(),
                        IconImage = videoIcon,
                        Heading = data.Element("Blogs_Heading").Value.ToString().Trim(),
                        MainImage = feedImageThumbnail, //data.Element("Blogs_SquareImagePath").Value.ToString(),
                        TimeStamp = data.Element("TimeElapsed").Value.ToString(),
                        SourceURL = data.Element("Blogs_SourceURL").Value.ToString()
                    });

                }
                catch (Exception)
                {
                    //throw;
                }               
            }
            httpClient.Dispose();

            if (lstLatest.Items.Count == 0)
            {
                lstLatest.ItemsSource = oc;
            }
            else
            {
                NotifyPropertyChanged();
            }

            httpClient.Dispose();
            progressRing.IsActive = false;
        }
0


source






More articles:


All Articles