ListBox Filtering

Question

There is a ListBox and TextBox , the first one is bound to ObservableCollection<Adress> , where Adress is

 public struct Adress { public Adress(string text, double x, double y) { Text = text; X = x; Y = y; } public string Text { get; set; }//Именно это свойство отображается в "ListboxItem" public double X { get; set; } public double Y { get; set; } }

TextBox bound to a property-string, in the setter of which I tried to filter, but all is in vain. I tried ICollectionView with the help of ICollectionView , but did not figure out how to achieve the desired result.

And now about what the desired result is - when entering text into a TextBox , those elements in ListBox 'e that contain this text (regardless of case) - remain visible, and the rest are “hidden” (I think just to use Visibility.Collapsed , but here all means will be good). Here I can not understand how to implement it without violating the principles of MVVM.

Arthur Edgarov Arthur Edgarov 857 one 6 27 · Accepted Answer · 2018-04-26T14:28:39

As a result, I figured it out myself, my own inattention was to blame for everything - I didn’t correctly specify Binding for TextBox :

 <TextBox Text="{Binding AdressFilterText}"/>

Thus, the following code is fully operational:

 <TextBox Text="{Binding AdressFilterText, UpdateSourceTrigger=PropertyChanged}"/> <ListBox ItemsSource="{Binding Adresses}"/>

And C #:

 public ObservableCollection<Adress> Adresses { get; set; } private ICollectionView _adressFilter = CollectionViewSource.GetDefaultView(Adresses); public string AdressFilterText { get => _adressFilterText; set { if(value != _adressFilterText) { _adressFilterText = value; OnPropertyChanged("AdressFilterText"); } _adressFilter.Filter = o => { if (((Adress)o).Text.ToLower().Contains(value.ToLower())) return true; else return false; }; } } private string _adressFilterText;

In my opinion, ICollectionView should be in View if you follow MVVM classics
@FoggyFinder, and how will the ViewModel know about it if it is in View ?
No way, if filtering is used only for presentation, then the VM does not need to be aware of what is currently displayed to the user
You can filter through and ICollectionView at the View level, if you understand correctly.

ListBox Filtering

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