Question

I have a simple property on my view model that is of type string. I want to bind this to a textbox so that changing the textbox updates the string and changing the string updates the textbox. Do I REALLY have a write a wrapper class around the string type that implements INotifyPropertyChanged, or am I missing something incredibly simple here?

Answer 1

It’s really easy to implement INotifyPropertyChanged. But what I would do, ViewModel classes almost always (if not always) inherit from DependencyObject; I would do this text property a DependencyProperty, which automatically notifies changes to whatever it’s bound to. You can use the propdp shortcut in C# (in visual studio 2008, not sure if 2005 too) to create a DependencyProperty faster, just type propdp and hit the Tab key twice. It would look something like this:

    public string SomeText
    {
        get { return (string)GetValue(SomeTextProperty); }
        set { SetValue(SomeTextProperty, value); }
    }

    // Using a DependencyProperty as the backing store for SomeText.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty SomeTextProperty =
        DependencyProperty.Register("SomeText", typeof(string), typeof(YourClassName), new UIPropertyMetadata(String.Empty));