How to bind ItemClick in MvxListView in MvxListView

mvvmcross, xamarin, xamarin.android

Solution

The `DataContext` for your person list item is a `Person` - so your `SelectDogCommand` needs to be part of the `Person` class - e.g. something like:

public class Person
{
    private string _name;
    private List<Dog> _hasDogs;

    public List<Dog> HasDogs
    {
      get { return _hasDogs; }
      set { _hasDogs = value; }
    }

    public string Name
    {
      get { return _name; }
      set { _name = value; }
    }

    private Cirrious.MvvmCross.ViewModels.MvxCommand<Dog> _selectDog;
    public System.Windows.Input.ICommand SelectDogCommand
    {
        get
        {
            _selectDog = _selectDog ?? new Cirrious.MvvmCross.ViewModels.MvxCommand<Dog>(dog => _parent.SelectDog(dog));
            return _selectDog;
        }
    }

    private FirstViewModel _parent;
    public Person(FirstViewModel parent)
    {
        _parent = parent;
    }
}

or alternatively you could get Person to inherit from MvxNavigatingObject (or MvxPropertyChanged or MvxViewModel) - in which case the ShowViewModel methods will be available there too.

Problem

In my example below I want to bind an ItemClick Command to the Item in the MvxListView. Here I have in my ViewModel a List of Person that contains a List of Dog. The ItemsSource HasDogs binding works fine. When MvvmCross is trying to bind ItemClick SelectDogCommand to the ICommand in the Viewmodel I get this Exception. ``` [0:] MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person [0:] MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person 12-04 15:05:03.062 I/mono-stdout(16338): MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person ``` Hope you can Help. Here is my example: ``` public class FirstViewModel:MvxViewModel { private List<Person> _persons; public List<Person> Persons { get { return _persons; } set { _persons = value; } } private Cirrious.MvvmCross.ViewModels.MvxCommand<Dog> _selectDog; public System.Windows.Input.ICommand SelectDogCommand { get { _selectDog = _selectDog ?? new Cirrious.MvvmCross.ViewModels.MvxCommand<Dog>(SelectDog); return _selectDog; } } private void SelectDog(Dog item) { ShowViewModel<DetailViewModel>(new DetailViewModel.Parameters{dog = item}); } } public class Person { private string _name; private List<Dog> _hasDogs; public List<Dog> HasDogs { get { return _hasDogs; } set { _hasDogs = value; } } public string Name { get { return _name; } set { _name = value; } } } public class Dog{...} ``` The Android View Xml: FirstView: ``` <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:local="http://schemas.android.com/apk/res-auto" ...> <TextView ... local:MvxBind="Text Persons" <Mvx.MvxListView ... local:MvxBind="ItemsSource Persons" local:MvxItemTemplate="@layout/item_person" /> </LinearLayout> ``` item_person: ``` <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:local="http://schemas.android.com/apk/res-auto" ... android:layout_height="200dp"> <TextView ... local:MvxBind="Text Name" /> <Mvx.MvxListView ... local:MvxBind="ItemsSource HasDogs; ItemClick SelectDogCommand" local:MvxItemTemplate="@layout/item_dog" /> </LinearLayout> ```

Original source