Implementation of bindable properties in Xamarin.Forms

BindableProperty.cs

///<summary>
///Provides a property that we can bind view model properties to. Notice that the name of the property
///follows the pattern of the using the instance property name followed by the word Property. 
//</summary>
public static BindableProperty LeftTitleProperty = 
    BindableProperty.Create<CustomHeaderBox, string>(ctrl => ctrl.LeftTitle,
        defaultValue: string.Empty,
        defaultBindingMode: BindingMode.TwoWay,
        propertyChanging: (bindable, oldValue, newValue) => {
            var ctrl = (CustomHeaderBox)bindable;
            ctrl.LeftTitle = newValue;
        });
        
//The property that handles getting and setting our label/property.
public string LeftTitle {
    get { return (string)GetValue(LeftTitleProperty); }
    set { 
        SetValue (LeftTitleProperty, value);
        //here we update the left title label
        LeftTitleLabel.Text = value;
    }
}

https://gist.githubusercontent.com/xeterixon/d1b33a3d5c6b40be8562/raw/b8895f02106ef962b3fc816e8077bc62fd8f64fc/bprop.template.xml