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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<object> bindingList = new ObservableCollection<object>();//数据源绑定List
private string editText = "";//编辑文本内容
/// <summary>
/// 注册依赖事件
/// </summary>
public static readonly DependencyProperty ItemsSourcePropertyNew = DependencyProperty.Register("MyItemsSource", typeof(IEnumerable), typeof(EditComboBox), new FrameworkPropertyMetadata(new PropertyChangedCallback(ValueChanged)));
/// <summary>
/// 数据源改变，添加数据源到绑定数据源
/// </summary>
/// <param name="d"></param>
/// <param name="e"></param>
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);
}
}
/// <summary>
/// 设置或获取ComboBox的数据源
/// </summary>
public IEnumerable MyItemsSource
{
get
{
return (IEnumerable)GetValue(ItemsSourcePropertyNew);
}
set
{
if (value == null)
ClearValue(ItemsSourcePropertyNew);
else
SetValue(ItemsSourcePropertyNew, value);
}
}
/// <summary>
/// 重写初始化
/// </summary>
/// <param name="e"></param>
protected override void OnInitialized(EventArgs e)
{
base.OnInitialized(e);
this.IsEditable = true;
this.IsTextSearchEnabled = false;
this.ItemsSource = bindingList;
}
/// <summary>
/// 下拉框获取焦点，首次搜索文本编辑框
/// </summary>
/// <param name="e"></param>
protected override void OnGotFocus(RoutedEventArgs e)
{
if (t)
FindTextBox(this);
else
t = false;
}
/// <summary>
/// 搜索编辑文本框，添加文本改变事件
/// </summary>
/// <param name="obj"></param>
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);
}
}
}
/// <summary>
/// 文本改变，动态控制下拉条数据源
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
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);
}
}
/// <summary>
/// 组合框关闭，数据源恢复
/// </summary>
/// <param name="e"></param>
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);
}
}
/// <summary>
/// 过滤符合条件的数据项，添加到数据源项中
/// </summary>
/// <param name="txt"></param>
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());
}
}
}
</div>
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
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
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