Question

Several answers to questions about check box binding, for example this one suggest that

<checkbox IsChecked="{Binding Path=MyProperty, Mode=TwoWay}"/> 

should work. What have I missed in the following code, which does not work?

<Window x:Class="TestBinding.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <CheckBox Name="checkBox1" IsChecked="{Binding Path=MyProperty, Mode=TwoWay}">CheckBox</CheckBox>
    </Grid>
</Window>

---

namespace TestBinding
{
    public partial class Window1 : Window
    {
        bool property = true;

        public Window1()
        {
            InitializeComponent();
        }

        public bool MyProperty
        {
            get
            {
                return property;
            }
            set
            {
                property = value;
            }
        }
    }
}

update

3 good answers, many thanks, I’d like to accept them all, but have accepted the first that mentioned DataContext which was the part that affected the binding direction I was most interested in. The TwoWay mode has turned out to be a red herring.
And thanks for the MVVM suggestions, I am using it but wanted this code to be as simple as possible

Answer 1

Implement INotifyPropertyChanged, and set the DataContext to “this” :

namespace TestBinding
{
    public partial class Window1 : Window, INotifyPropertyChanged
    {
        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(String _Prop)
        {
            if (PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(_Prop));
            }
        }
        #endregion

        bool property = true;

        public Window1()
        {
            InitializeComponent();
            this.DataContext = this;
        }

        public bool MyProperty
        {
            get
            {
                return property;
            }
            set
            {
                property = value;
                RaisePropertyChanged("MyProperty");
            }
        }
    }
}