Question

I have a problem with two way binding a TextBox content to a property in another class. Searching stackoverflow gave a lot of tips/solutions but none seem to work.

In my XAML code I have:

< TextBox ... Width="336" IsReadOnly="True"
 Text="{Binding Path=AssignedClearProgram, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>

(… I removed all non important items)

In the accompanies cs code I have:

public CombiWindow(Combi combi)
{
    ViewModel = new CombiViewModel(combi);
    DataContext = ViewModel;
}

In the CombiViewModel:

    [UsedImplicitly]
    public string AssignedClearProgram { get; set; }

It seems that the first time I assign AssignedClearProgram, the textbox is filled with the text that I set, however after the window is displayed and AssignedClearProgram gets updated from the code (i.e. the set method is called), the data is not updated in the screen.

Does anybody have a solution to update the textbox when this variable is changed?

Kind regards,

Michel

Answer 1

Your viewmodel class needs to implement INotifyPropertyChanged and you need to raise that interface’s event whenever you change the property. Then the binding will spot changes and update the textbox.