add ignoreTextChanged

src/Shared/HandyControl_Shared/Controls/Input/AutoCompleteTextBox/AutoCompleteTextBox.cs

@@ -0,0 +1,150 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using HandyControl.Data;
+using HandyControl.Tools.Helper;
+
+namespace HandyControl.Controls
+{
+    [TemplatePart(Name = SearchTextBox, Type = typeof(System.Windows.Controls.TextBox))]
+    public class AutoCompleteTextBox : ComboBox
+    {
+        private const string SearchTextBox = "PART_SearchTextBox";
+
+        private bool ignoreTextChanging;
+
+        private System.Windows.Controls.TextBox _searchTextBox;
+
+        private object _selectedItem;
+
+        static AutoCompleteTextBox()
+        {
+            TextProperty.OverrideMetadata(typeof(AutoCompleteTextBox), new FrameworkPropertyMetadata(default(string), FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));
+        }
+
+        public override void OnApplyTemplate()
+        {
+            if (_searchTextBox != null)
+            {
+                _searchTextBox.GotFocus -= SearchTextBoxGotFocus;
+                _searchTextBox.KeyDown -= SearchTextBoxKeyDown;
+                _searchTextBox.TextChanged -= SearchTextBoxTextChanged;
+            }
+
+            base.OnApplyTemplate();
+
+            _searchTextBox = GetTemplateChild(SearchTextBox) as System.Windows.Controls.TextBox;
+            if (_searchTextBox != null)
+            {
+                _searchTextBox.GotFocus += SearchTextBoxGotFocus;
+                _searchTextBox.PreviewKeyDown += SearchTextBoxKeyDown;
+                _searchTextBox.TextChanged += SearchTextBoxTextChanged;
+            }
+        }
+
+        protected override void OnSelectionChanged(SelectionChangedEventArgs e)
+        {
+            if (e.AddedItems.Count > 0)
+            {
+                _selectedItem = e.AddedItems[0];
+            }
+        }
+
+        protected override void OnDropDownClosed(EventArgs e)
+        {
+            base.OnDropDownClosed(e);
+
+            if (ItemContainerGenerator.ContainerFromItem(_selectedItem) is AutoCompleteTextBoxItem boxItem)
+            {
+                ignoreTextChanging = true;
+
+                _searchTextBox.Text = BindingHelper.GetString(boxItem.Content, DisplayMemberPath);
+                _searchTextBox.CaretIndex = _searchTextBox.Text.Length;
+
+                ignoreTextChanging = true;
+
+                Text = _searchTextBox.Text;
+
+                ignoreTextChanging = false;
+            }
+        }
+
+        protected override bool IsItemItsOwnContainerOverride(object item) => item is AutoCompleteTextBoxItem;
+
+        protected override DependencyObject GetContainerForItemOverride() => new AutoCompleteTextBoxItem();
+
+        private void SearchTextBoxTextChanged(object sender, TextChangedEventArgs e)
+        {
+            _selectedItem = null;
+            SelectedIndex = -1;
+
+            if (ignoreTextChanging)
+            {
+                ignoreTextChanging = false;
+                return;
+            }
+
+            Text = _searchTextBox.Text;
+            if (string.IsNullOrEmpty(Text))
+            {
+                SetCurrentValue(IsDropDownOpenProperty, ValueBoxes.FalseBox);
+                _searchTextBox.Focus();
+            }
+            else if (_searchTextBox.IsFocused)
+            {
+                SetCurrentValue(IsDropDownOpenProperty, ValueBoxes.TrueBox);
+            }
+        }
+
+        private void SearchTextBoxKeyDown(object sender, KeyEventArgs e)
+        {
+            if (e.Key == Key.Up)
+            {
+                var index = SelectedIndex - 1;
+                if (index < 0)
+                {
+                    index = Items.Count - 1;
+                }
+
+                UpdateTextBoxBySelectedIndex(index);
+            }
+            else if (e.Key == Key.Down)
+            {
+                var index = SelectedIndex + 1;
+                if (index >= Items.Count)
+                {
+                    index = 0;
+                }
+
+                UpdateTextBoxBySelectedIndex(index);
+            }
+            else if (e.Key == Key.Enter)
+            {
+                SetCurrentValue(IsDropDownOpenProperty, ValueBoxes.FalseBox);
+                e.Handled = true;
+            }
+        }
+
+        private void UpdateTextBoxBySelectedIndex(int selectedIndex)
+        {
+            ignoreTextChanging = true;
+
+            if (ItemContainerGenerator.ContainerFromIndex(selectedIndex) is AutoCompleteTextBoxItem boxItem)
+            {
+                _searchTextBox.Text = BindingHelper.GetString(boxItem.Content, DisplayMemberPath);
+                _searchTextBox.CaretIndex = _searchTextBox.Text.Length;
+
+                SelectedIndex = selectedIndex;
+            }
+        }
+
+        private void SearchTextBoxGotFocus(object sender, RoutedEventArgs e)
+        {
+            if (!string.IsNullOrEmpty(Text))
+            {
+                SetCurrentValue(IsDropDownOpenProperty, ValueBoxes.TrueBox);
+            }
+        }
+    }
+}

src/Shared/HandyControl_Shared/Controls/Input/AutoCompleteTextBox/AutoCompleteTextBoxItem.cs

@@ -0,0 +1,9 @@
+using System.Windows.Controls;
+
+namespace HandyControl.Controls
+{
+    public class AutoCompleteTextBoxItem : ComboBoxItem
+    {
+        
+    }
+}