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带搜索的ComboBox就是给ComboBox一个依赖属性的ItemSource，然后通过数据源中是否包含要查询的值，重新给ComboBox绑定数据源。
public class EditComboBox : ComboBox { private bool t = true;//首次获取焦点标志位 private ObservableCollection bindingList = new ObservableCollection();//数据源绑定List private string editText = "";//编辑文本内容 /// /// 注册依赖事件 /// public static readonly DependencyProperty ItemsSourcePropertyNew = DependencyProperty.Register("MyItemsSource", typeof(IEnumerable), typeof(EditComboBox), new FrameworkPropertyMetadata(new PropertyChangedCallback(ValueChanged))); /// /// 数据源改变，添加数据源到绑定数据源 /// /// /// private static void ValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { EditComboBox ecb = d as EditComboBox; ecb.bindingList.Clear(); //遍历循环操作 foreach (var item in ecb.MyItemsSource) { ecb.bindingList.Add(item); } } /// /// 设置或获取ComboBox的数据源 /// public IEnumerable MyItemsSource { get { return (IEnumerable)GetValue(ItemsSourcePropertyNew); } set { if (value == null) ClearValue(ItemsSourcePropertyNew); else SetValue(ItemsSourcePropertyNew, value); } } /// /// 重写初始化 /// /// protected override void OnInitialized(EventArgs e) { base.OnInitialized(e); this.IsEditable = true; this.IsTextSearchEnabled = false; this.ItemsSource = bindingList; } /// /// 下拉框获取焦点，首次搜索文本编辑框 /// /// protected override void OnGotFocus(RoutedEventArgs e) { if (t) FindTextBox(this); else t = false; } /// /// 搜索编辑文本框，添加文本改变事件 /// /// private void FindTextBox(DependencyObject obj) { for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++) { DependencyObject child = VisualTreeHelper.GetChild(obj, i); if (child!=null && child is TextBox) { //注册文本改变事件 (child as TextBox).TextChanged += EditComboBox_TextChanged; } else { FindTextBox(child); } } } /// /// 文本改变，动态控制下拉条数据源 /// /// /// private void EditComboBox_TextChanged(object sender, TextChangedEventArgs e) { TextBox tb = sender as TextBox; if(tb.IsFocused) { this.IsDropDownOpen = true; if (editText == this.Text) return; editText = this.Text; SetList(editText); } } /// /// 组合框关闭，数据源恢复 /// /// protected override void OnDropDownClosed(EventArgs e) { base.OnDropDownClosed(e); if (MyItemsSource == null) return; foreach (var item in MyItemsSource) { if (!bindingList.Contains(item)) bindingList.Add(item); } } /// /// 过滤符合条件的数据项，添加到数据源项中 /// /// private void SetList(string txt) { try { string temp1 = ""; string temp2 = ""; if (MyItemsSource == null) return; foreach (var item in MyItemsSource) { temp1 = item.GetType().GetProperty(this.DisplayMemberPath).GetValue(item, null).ToString(); if (string.IsNullOrEmpty(this.SelectedValuePath)) { temp2 = ""; } else { temp2 = item.GetType().GetProperty(this.SelectedValuePath).GetValue(item, null).ToString(); } if(temp1.Contains(txt)||temp2.StartsWith(txt)) { if (!bindingList.Contains(item)) bindingList.Add(item); } else if (bindingList.Contains(item)) { bindingList.Remove(item); } } } catch (Exception ex) { MessageBox.Show(ex.ToString()); } } }
调用方法就是将数据源绑定到MyItemsSource上，剩下的就和原有的ComboBox用法一样了。
效果演示
转载于:https://www.cnblogs.com/lonelyxmas/p/10789483.html
