WPF two-way binding not working

Question

I have a data context (UserPreferences) assigned to my main window, and a textbox that binds two-way to a property within one of the data context\'s properties

Answer 1

Not an answer but wanted to post the code that works on my machine to help OP...

Complete xaml page...

Complete code behind...

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Xml.Serialization;

namespace WpfApplication1
{
    /// 

    /// Interaction logic for Window1.xaml
    /// 
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
            DataContext = new UserPreferences();
        }

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            ((UserPreferences) DataContext).SelectedCollectionDevice.ComPort = 11;
        }

    }

    /// 

    /// Provides a series of user preferences.
    /// 
    [Serializable]
    public class UserPreferences : INotifyPropertyChanged
    {
        private CollectionDevice selectedCollectionDevice;

        public UserPreferences()
        {
            this.AvailableCollectionDevices = new List();

            var yuma1 = new CollectionDevice
            {
                BaudRate = 4800,
                ComPort = 31,
                DataPoints = 1,
                Name = "Trimble Yuma 1",
                WAAS = true
            };

            var yuma2 = new CollectionDevice
            {
                BaudRate = 4800,
                ComPort = 3,
                DataPoints = 1,
                Name = "Trimble Yuma 2",
                WAAS = true
            };

            var toughbook = new CollectionDevice
            {
                BaudRate = 4800,
                ComPort = 3,
                DataPoints = 1,
                Name = "Panasonic Toughbook",
                WAAS = true
            };


            var other = new CollectionDevice
            {
                BaudRate = 0,
                ComPort = 0,
                DataPoints = 0,
                Name = "Other",
                WAAS = false
            };

            this.AvailableCollectionDevices.Add(yuma1);
            this.AvailableCollectionDevices.Add(yuma2);
            this.AvailableCollectionDevices.Add(toughbook);
            this.AvailableCollectionDevices.Add(other);

            this.SelectedCollectionDevice = this.AvailableCollectionDevices.First();
        }

        /// 

        /// Gets or sets the GPS collection device.
        /// 
        public CollectionDevice SelectedCollectionDevice
        {
            get
            {
                return selectedCollectionDevice;
            }
            set
            {
                selectedCollectionDevice = value;
                this.OnPropertyChanged("SelectedCollectionDevice");
            }
        }

        /// 

        /// Gets or sets a collection of devices that can be used for collecting GPS data.
        /// 
        [XmlIgnore]
        public List AvailableCollectionDevices { get; set; }

        public event PropertyChangedEventHandler PropertyChanged;

        /// 

        /// Notifies objects registered to receive this event that a property value has changed.
        /// 
        /// The name of the property that was changed.
        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }

    /// 

    /// CollectionDevice model
    /// 
    [Serializable]
    public class CollectionDevice : INotifyPropertyChanged
    {
        /// 

        /// Gets or sets the COM port.
        /// 
        private int comPort;

        /// 

        /// Gets or sets a value indicating whether [waas].
        /// 
        private bool waas;

        /// 

        /// Gets or sets the data points.
        /// 
        private int dataPoints;

        /// 

        /// Gets or sets the baud rate.
        /// 
        private int baudRate;

        /// 

        /// Gets or sets the name.
        /// 
        public string Name { get; set; }

        /// 

        /// Gets or sets the COM port.
        /// 
        public int ComPort
        {
            get
            {
                return this.comPort;
            }

            set
            {
                this.comPort = value;
                this.OnPropertyChanged("ComPort");
            }
        }

        /// 

        /// Gets or sets the COM port.
        /// 
        public bool WAAS
        {
            get
            {
                return this.waas;
            }

            set
            {
                this.waas = value;
                this.OnPropertyChanged("WAAS");
            }
        }

        /// 

        /// Gets or sets the COM port.
        /// 
        public int DataPoints
        {
            get
            {
                return this.dataPoints;
            }

            set
            {
                this.dataPoints = value;
                this.OnPropertyChanged("DataPoints");
            }
        }

        /// 

        /// Gets or sets the COM port.
        /// 
        public int BaudRate
        {
            get
            {
                return this.baudRate;
            }

            set
            {
                this.baudRate = value;
                this.OnPropertyChanged("BaudRate");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        /// 

        /// Notifies objects registered to receive this event that a property value has changed.
        /// 
        /// The name of the property that was changed.
        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public override string ToString()
        {
            return this.Name;
        }
    }
}