Binding to two or more control properties using Caliburn (micro)

Question

The problem I'm trying to solve is fairly straight forward, I'm using Microsoft.Phone.Controls and I'm trying to bind to two properties of ToggleSwitch in my MainPageViewModel so I can capture the state of the ToggleSwitch and change its content from 'on/off' to 'distance/time' for example.

What I'm doing doesn't work, it's something to do with conventions that I haven't quite figured out from the docs (RTFM...). This doesn't work:

using System;
using System.Windows.Data;
using System.Collections.Generic;
using Caliburn.Micro;
using Microsoft.Phone.Controls;

public class AppBootstrapper : PhoneBootstrapper
{
    PhoneContainer container;

    protected override void Configure()
    {
        container = new PhoneContainer(RootFrame);

        container.RegisterPhoneServices();
        container.PerRequest<MainPageViewModel>();

        AddCustomConventions();
    }

    private static void AddCustomConventions()
    {
        ConventionManager.AddElementConvention<ToggleSwitch>(ToggleSwitch.IsCheckedProperty, "IsChecked", "Click")
            .ApplyBinding = (viewModelType, path, property, element, convention) =>
            {
                //Default binding to "IsChecked" property
                if (!ConventionManager.SetBinding(viewModelType, path + ".IsChecked", property, element, convention))
                    return false;

                if (!ConventionManager.HasBinding(element, ToggleSwitch.ContentProperty))
                {
                    var binding = new Binding(path + ".Content");

                    BindingOperations.SetBinding(element, ToggleSwitch.ContentProperty, binding);
                }

                return true;
            };
    }
}

and

    bool fixedDistance = true;
    public bool FixedDistance
    {
        get
        {
            return fixedDistance;
        }
        set
        {
            fixedDistance = value;
            NotifyOfPropertyChange(() => FixedDistance);

            if (fixedDistance)
            {
                FixedDistanceContent = "Distance";
            }
            else
            {
                FixedDistanceContent = "Time";
            }
        }
    }

    string fixedDistanceContent;

    public string FixedDistanceContent
    {
        get
        {
            return fixedDistanceContent;
        }
        set
        {
            fixedDistanceContent = value;
            NotifyOfPropertyChange(() => FixedDistanceContent);
        }
    }

where the ToggleSwitch has the xaml Name=FixedDistance.

I'm naively (and clearly incorrectly) expecting the ToggleSwitch.IsChecked to be bound to the FixedDistance property, and the ToggleSwitch.Content to be bound to FixedDistanceContent.

Thanks!

Answer 1

It looks like this:

        ConventionManager.AddElementConvention<ToggleSwitch>(
            ToggleSwitch.IsCheckedProperty,
            "IsChecked",
            "Click");
            .ApplyBinding = (viewModelType, path, property, element, convention) =>
        {
            if (!ConventionManager.SetBinding(viewModelType, path, property, element, convention))
                return false;

            if (ConventionManager.HasBinding(element, ToggleSwitch.ContentProperty)) return true;

            var binding = new Binding(path + "Content") { Mode = BindingMode.TwoWay };
            BindingOperations.SetBinding(element, ToggleSwitch.ContentProperty, binding);

            return true;
        };

does the trick.