WPF How to create a Custom Textbox with validation and binding

Question

I\'m developing a custom text box for currency editing.
I\'ve seen some ready to use ones, but they\'re complicated and/or not really usable, forcing you to bad practi

Answer 1

create new Dependency Property like this

public static readonly DependencyProperty ValueProperty = 
     DependencyProperty.Register(
         "Value", 
         typeof(decimal?),
         typeof(CurrencyTextBox),
         new FrameworkPropertyMetadata(
                     new decimal?(), 
                     FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, 
                     new PropertyChangedCallback(ValuePropertyChanged)));

private static void ValuePropertyChanged(
                         DependencyObject d,
                         DependencyPropertyChangedEventArgs e)
{
    CurrencyTextBox x = (CurrencyTextBox)d;
    x.Value = (decimal?)e.NewValue;
}

and then bind to this new property