How to create view's actions listener for MvxItemTemplate

Question

I have a view which contains an MvxListView and a form. I can hide the softkeyboard using the following code in my view\'s code (as this is pure view concerns)

v         


        

Answer 1

I think the easy way to do this is to use a custom 'View' within the listitem.

Note: that 'View' here refers to Android Views - not Model-View-ViewModel views - sorry for the naming confusion!

Creating custom views is easy to do...

Just create a custom View - e.g.

namespace Angevelle.App1.UI.Droid.Controls
{
    public class MyText : EditText
    {
        public MyText(Context context, IAttributeSet attrs)
            : base(context, attrs)
        {
            this.EditorAction += OnEditorAction;
        }

        private void OnEditorAction(object sender, EditorActionEventArgs editorActionEventArgs)
        {
            if (editorActionEventArgs.ActionId == ImeAction.Done)
            {
                // this code not tested - but something like this should work
                var imm = (InputMethodManager)Context.GetSystemService(Context.InputMethodService);
                imm.HideSoftInputFromWindow(WindowToken, 0);
            }
        }
    }
}

Then you can use that View in your AXML just as you do Android or Mvx views:

<angevelle.app1.ui.droid.controls.MyText
         android:layout_height=....
     />

If you are finding angevelle.app1.ui.droid.controls too verbose, then you could shorten this using an abbreviation in setup.cs:

    protected override IDictionary<string, string> ViewNamespaceAbbreviations
    {
        get
        {
            var abbreviations = base.ViewNamespaceAbbreviations;
            abbreviations["Abv"] = "angevelle.app1.ui.droid.controls";
            return abbreviations;
        }
    }

then you can just use:

<Abv.MyText
         android:layout_height=....
     />

---

An alternative approach might be to somehow customise the list...

If you ever do need to completely customise a listview and its adapter, then this can be easily done using the same type of technique - inherit from MvxBindableListView in your UI project:

public class MyListView : MvxBindableListView
{
        public MyListView(Context context, IAttributeSet attrs);
            : base(context, attrs, new MyListAdapter(context))
        {
        }
}

where MyListAdapter overrides the view creation:

public class MyListAdapter : MvxBindableListAdapter
{
    public MyListAdapter(Context context)
        : base(context)
    {
    }

    // put your custom Adapter code here... e.g.:
    protected override MvxBindableListItemView CreateBindableView(object source, int templateId)
    {
        return new MySpecialListItemView(_context, _bindingActivity, templateId, source);
    }
}

where MySpecialListItemView inherits from MvxBindableListItemView but adds your own custom features.

Using this approach your list would then change from:

<Mvx.MvxBindableListView
      ....
     />

to:

<Abv.MyListView
      ....
     />

---

For more examples of custom views, take a look around GitHub - e.g. at some of the Calendar, ColorPicker, ActionBar projects in https://github.com/Cheesebaron

Don't expect your custom controls to render in the xamarin designer (well, not yet...)

---

Two final notes...

1. To reuse code... you might want to put that HideSoftInputFromWindow functionality in an extension method somehow so that you can just call anyEditText.HideOnDone()

2. Be careful when using the Monodroid/monotouch events on Views/UIViews - these events tend to use the native delegates/listeners - and so sometimes you can find that attaching something to subscribe to one event can unattach something else! Generally you are OK as long as you don't mix and match the C# event subscriptions at the same time as the native listener/delegate handlers.