Binding data of multiple classes to single list view/xamarin forms

Question

Hello how can i bind data of multiple classes to a single list view through xaml. I sucessfully bind data from single class to a lisview but when i try to bind data of more than one classes it didn't show anything in xaml.

Answer 1

You cant't do that 'directly'. As all UIElement controls have only one BindingContext property, you can bind only one objet at a time.

In MVVM patterns, you implement ViewModel classes to group all the needed data to display on the associated page...

So for your 'Listview', I suggest you to make a property in your ViewModel that references a new object that is simply the aggregation of all classes you want to connect to your listview.

A simple exemple:

/// Data A needed for your listview 
public class DataA { ... }

/// Data B needed for your listview 
public class DataB { ... }

///
/// You will make a property of this type into your viewModel
///
public class ListviewAggregatedData : INotifyPropertyChanged
{
    private DataA _listviewDataPart1;
    private DataB _listviewDataPart2;

    public DataA ListViewDataPart1
    {
        get => _listviewDataPart1;
        set {  _listviewDataPart1 = value; PropertyChanged?.Invoke(...); }
    }

    public DataA ListViewDataPart2
    {
        get => _listviewDataPart2;
        set {  _listviewDataPart2 = value; PropertyChanged?.Invoke(...); }
    }

    // ....
}

And in your xaml, presuming your viewModel implements a property of type ListviewAggregatedData called 'VmAggregatedDataProp', You could have something like that:

        <ListView
            BindingContext="{Binding VmAggregatedDataProp}"
            Header="{Binding ListViewDataPart1.Title}"
            ItemsSource="{Binding ListViewDataPart2.AllMyItems}"
            />

Binding names in this example must be replaced by your own properties... Tell me if it s clear...