您如何绑定到类属性？

Question

Is it possible to bind to the property inside a class?

Say I have in my ViewModel a property like this (my ViewModel inherits from BindableBase)

    private PointOfView _userPointOfView;
    public PointOfView UserPointOfView
    {
        get { return _userPointOfView; }
        set{ SetProperty(ref _userPointOfView, value); }
    }

Where PointOfView class has some property say a string variable called 'UserString'

And in my application I'm setting my datacontext like this

    public MainPage()
    {
        this.InitializeComponent();
        DataContext = App.ViewModel;


        PointOfView POV = bew PointOfView();
        POV.UserString = "Test";
        App.ViewModel.UserPointOfView = POV;

    }

What I want to do in my XAML is something like

<TextBlock Text="{Binding UserPointOfView.UserString, Mode="OneWay"}"></TextBlock>

Anyway I tried something like that but it never update the textblock on the xaml page.

Does anyone know if there is a way to do this? It would be some much easier and save a lot of code duplication in my ViewModel, instead of creating so many properties for every property inside the class.

Answer 1

It is possible, and very common to bind to a 'nested' property. If your bound values are not appearing, then you may not have the DataContext set correctly. Use the debug output window for a hint as to what is not binding correctly.

Also, if your PointOfView class does not implement INotifyPropertyChanged, then your binding won't automatically update. It will only display the value as it first appeared when the binding was established.