In MvvmCross how do I do custom bind properties

Question

I am using `MvxBindableListView` to bind a `List<>` of data objects to a `ListView`. The layout I am using for the rows has several `TextView`s. I am successfully binding the `Text` property for each of these to a property in my data object, but I have found that I cannot bind to `TextColor` as that property does not exist in Mono For Android `TextView`s; instead you have use the `SetTextColor()` method. So how can I bind a data object property to a method?! Below is the code I tried to use: ``` ```

Accepted Answer

There's an example of adding a custom 2-way binding for "IsFavorite" in the Conference sample - see:

- the binding - https://github.com/slodge/MvvmCross/blob/master/Sample%20-%20CirriousConference/Cirrious.Conference.UI.Droid/Bindings/FavoritesButtonBinding.cs

- the binding setup in `FillTargetFactories` in https://github.com/slodge/MvvmCross/blob/master/Sample%20-%20CirriousConference/Cirrious.Conference.UI.Droid/Setup.cs

This example is explained a bit further in: MVVMCross Bindings in Android

For a one-way "source-to-target" custom binding, the code should be a bit simpler - you only need to handle the `SetValue` - and don't need to invoke `FireValueChanged` in any event handling code.

For textColor, I'd imagine the binding would look a bit like:

```
public class MyCustomBinding
    : MvxBaseAndroidTargetBinding
{
    private readonly TextView _textView;

public MyCustomBinding(TextView textView)
    {
        _textView = textView;
    }

public override void SetValue(object value)
    {
        var colorValue = (Color)value;
        _textView.SetTextColor(colorValue);
    }

public override Type TargetType
    {
        get { return typeof(Color); }
    }

public override MvxBindingMode DefaultMode
    {
        get { return MvxBindingMode.OneWay; }
    }
}
```

and would be setup with:

```
    protected override void FillTargetFactories(MvvmCross.Binding.Interfaces.Bindings.Target.Construction.IMvxTargetBindingFactoryRegistry registry)
    {
        base.FillTargetFactories(registry);

registry.RegisterFactory(new MvxCustomBindingFactory<TextView>("TextColor", (textView) => new MyCustomBinding(textView)));
    }
```

Note: I've not compiled this example code - when you do get it working, please come back and correct this pseudo-code :)

In MvvmCross how do I do custom bind properties

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