A 'Binding' can only be set on a DependencyProperty of a DependencyObject

Question

From a custom control based on TextBox, I created a property named Items, in this way:

public class NewTextBox : TextBox
{
    publ         


        

Answer 1

To solve this exception you need to change the property Items and add a DependencyProperty that will work as a "link" in XAML. The class will be:

public class AutocompleteTextBox : TextBox
{
    public ItemCollection Items
    {
        get {
            return (ItemCollection)GetValue(ItemsProperty); }
        set {
            SetValue(ItemsProperty, value); }
    }

    public static readonly DependencyProperty ItemsProperty =
        DependencyProperty.Register(
            "Items",
            typeof(ItemCollection),
            typeof(AutocompleteTextBox),
            new PropertyMetadata(default(ItemCollection), OnItemsPropertyChanged));

    private static void OnItemsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        // AutocompleteTextBox source = d as AutocompleteTextBox;
        // Do something...
    }