JD2022-TU1/main/tools/modules/JD.Guinness.WPF.Module/Behavior/AutoCompleteBoxBehavior.cs

using System.Windows;
using System.Windows.Input;
using ActiproSoftware.Windows.Controls.Editors;

namespace JD.Guinness.WPF.Module.Behavior
{
    public static class AutoCompleteBoxBehavior
    {
        public static readonly DependencyProperty ShowAllOnOpenProperty;

        static AutoCompleteBoxBehavior()
        {
            ShowAllOnOpenProperty = DependencyProperty.RegisterAttached("ShowAllOnOpen", typeof(bool), typeof(AutoCompleteBoxBehavior), new PropertyMetadata(OnShowAllOnOpenChanged));
        }

        private static void OnShowAllOnOpenChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
        {
            if (target is AutoCompleteBox autoCompleteBox)
            {
                if (autoCompleteBox.GetShowAllOnOpen())
                {
                    autoCompleteBox.PreviewKeyDown += OnAutoCompleteBoxPreviewKeyDown;
                    autoCompleteBox.PreviewMouseLeftButtonDown += OnAutoCompleteBoxMouseLeftButtonDown;
                    autoCompleteBox.TextChanged += OnAutoCompleteBoxTextChanged;
                }
                else
                {
                    autoCompleteBox.PreviewKeyDown -= OnAutoCompleteBoxPreviewKeyDown;
                    autoCompleteBox.PreviewMouseLeftButtonDown -= OnAutoCompleteBoxMouseLeftButtonDown;
                    autoCompleteBox.TextChanged -= OnAutoCompleteBoxTextChanged;
                }
            }
        }

        private static void OnAutoCompleteBoxPreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (sender is AutoCompleteBox autoCompleteBox && !autoCompleteBox.DataFilter.IsEnabled)
            {
                autoCompleteBox.DataFilter.IsEnabled = true;
            }
        }

        private static void OnAutoCompleteBoxMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            if (sender is AutoCompleteBox autoCompleteBox && !autoCompleteBox.IsPopupOpen)
            {
                autoCompleteBox.DataFilter.IsEnabled = false;
            }
        }

        private static void OnAutoCompleteBoxTextChanged(object sender, AutoCompleteBoxEventArgs e)
        {
            if (sender is AutoCompleteBox autoCompleteBox && string.IsNullOrEmpty(autoCompleteBox.Text))
            {
                autoCompleteBox.SelectedItem = null;
            }
        }

        public static bool GetShowAllOnOpen(this DependencyObject obj) => (bool)obj.GetValue(ShowAllOnOpenProperty);

        public static void SetShowAllOnOpen(this DependencyObject obj, bool value) => obj.SetValue(ShowAllOnOpenProperty, value);
    }
}