TextBox - binding property doesn't refresh itself

Question

Hi I have a textbox which Text property is bound like that

   <TextBox Name="txtBox">
        <TextBox.Text>
            <Binding Path="Data">

            </Binding>
        </TextBox.Text>
    </TextBox>

The filed Data can be changed in various places in my program. However if I change filed Data in ahother control, the t txtBox Text property does't refresh itself. I still can see the old value(despite the fact that Data filed has been changed). Is there any way to force textbox to refresh itselft or sth?

Answer 1

does your Data property owner object implement INotifyPropertyChanged? if no than implemet it and fire PropertyChanged When your set property is called

Answer 2

In order for your textbox to know when the data it's bound to changes, the class that it is bound to must implement INotifyPropertyChanged. Below is an example in C#. If you bind a textbox to the property Data, the textbox should update when the Data property's setter is executed. Note that INotifyPropertyChanged will require a reference to the System.ComponentModel namespace (a Using in C# or Imports in VB).

public class MyData : INotifyPropertyChanged
{
    string _data;

    public event PropertyChangedEventHandler PropertyChanged;

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

    public string Data
    {
        get
        {
            return _data;
        }

        set
        {
            _data = value;
            this.OnPropertyChanged("Data");
        }
    }
}