Simple databinding scenario

[yoyosh]

I`m trying to simulate simple two-way databinding mechanism. I have declared simple class for that purpose:

public class Car : INotifyPropertyChanged
     {        
         string color;
 
         public string Color
         {
             get { return color; }
             set
             {
                 color = value;
                 OnPropertyChanged("Color");
             }
         }
 
         
         
         public event PropertyChangedEventHandler PropertyChanged;
 
         void OnPropertyChanged(string propertyName)
         {
             if (PropertyChanged != null)
             {
                 PropertyChanged(null, new PropertyChangedEventArgs(propertyName));
             }
         }

I have also created object of that class in Window1.cs file:

public partial class Window1 : Window
     {
         Car veh = new Car();
 
 
         public Window1()
         {
             InitializeComponent();
 
             veh.Color="red";
 
             this.DataContext = veh;
         }
 ...

I have binded this object`s color property for a textbox:

 <TextBox Canvas.Left="276" Canvas.Top="66" Height="19.277" Width="101">
             <TextBox.Text>
                 <Binding Path="Color" Mode="TwoWay"></Binding>
             </TextBox.Text>
         </TextBox>

Value in this textbox doesn`t refresh however when property of business object changes. What is wrong?

[gstercken]

This happens because in your OnPropertyChanged() implementation, you are passing null as the source object. You should pass a reference to the changed object ('this', in this case) instead:

void OnPropertyChanged(string propertyName)
{
    if (PropertyChanged != null)
    {
        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}