WPF自定义TreeView显示结构通用类

　　在WPF中，专门有HierarchicalDataTemplate用于自定义显示TreeView和ListBox的层次结构，结合后台定义的数据，得以实现五花八门的外观。我现在先简要说明一下HierarchicalDataTemplate的使用方式：

public class DataItem
{
public string Header { get; set; }
public IList<DataItem> Childs { get; set; }
}

　　上面是树的一个结点类，包括了一个Header字段和子结点列表，下面则是对应的前台代码：

<Grid>
<Grid.Resources>
　　　　<HierarchicalDataTemplate x:Key="myDataTemplate" ItemsSource="{Binding Childs}">
　　　　　　<Label Content="{Binding Header}" />
　　　　</HierarchicalDataTemplate>
　　</Grid.Resources>
　　 <TreeView x:Name="TV_Test" ItemTemplate="{StaticResource myDataTemplate}" />
</Grid>

　　注意到，HierarchicalDataTemplate的ItemsSource就是层叠显示的关键，它可以遍历对应数据的所有Childs字段，并显示成<Label ... />的形式。接下来，把DataItem类型的数据集合赋给TreeView控件的ItemSource就完成了树形结构的显示：

List<DataItem> dataList = new List<DataItem>();
DataItem item1 = new DataItem { Header = "结点1" };
item1.Childs = new List<DataItem>();
item1.Childs.Add(new DataItem { Header = "结点1-1" });
item1.Childs.Add(new DataItem { Header = "结点1-2" });
dataList.Add(item1);
dataList.Add(new DataItem { Header = "结点2" });
TV_Test.ItemsSource = dataList;

　　所得结果如下图所示:

通用树结点类

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;

namespace EntityFramework.Common
{
/// <summary>
/// 实现了INotifyPropertyChanged接口通知的轻量级基类
/// </summary>
public abstract class ObservableBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;

protected void RaisePropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}

/// <summary>
/// 树数据类
/// </summary>
public class TreeViewData : ObservableBase
{
#region 私有字段

private string _Header;
private object _Tag;
private TreeViewData _Parent;
private ObservableCollection<TreeViewData> _Childs = new ObservableCollection<TreeViewData>();

#endregion

#region 公有属性

/// <summary>
/// 名字
/// </summary>
public string Header
{
get { return _Header; }
set { _Header = value; RaisePropertyChanged("Header"); }
}

/// <summary>
/// 标签
/// </summary>
public object Tag
{
get { return _Tag; }
set { _Tag = value; RaisePropertyChanged("Tag"); }
}

/// <summary>
/// 父项
/// </summary>
public TreeViewData Parent
{
get { return _Parent; }
set { _Parent = value; RaisePropertyChanged("Parent"); }
}

/// <summary>
/// 子项
/// </summary>
public ObservableCollection<TreeViewData> Childs
{
get { return _Childs; }
set { _Childs = value; RaisePropertyChanged("Childs"); }
}

#endregion

#region 方法函数

public TreeViewData() { }

public TreeViewData(string header)
{
_Header = header;
}

public TreeViewData(string header, object tag, TreeViewData parent = null)
{
_Header = header;
_Tag = tag;
_Parent = parent;
}

/// <summary>
/// 添加子元素
/// </summary>
/// <param name="childs">子元素</param>
/// <returns>个数</returns>
public void AddChild(TreeViewData child)
{
child.Parent = this;
_Childs.Add(child);
}

/// <summary>
/// 添加子元素集合
/// </summary>
/// <param name="childs">子元素</param>
/// <returns>个数</returns>
public int AddChilds(IEnumerable<TreeViewData> childs)
{
int nCount = 0;
foreach (TreeViewData item in childs)
{
AddChild(item); ++nCount;
}
return nCount;
}

/// <summary>
/// 将指定名称的所有子节点从父元素中移除
/// </summary>
/// <param name="parent">父元素</param>
/// <param name="name">子节点名称</param>
public void RemoveChilds(TreeViewData parent, string name)
{
for (int i = 0; i < parent.Childs.Count; ++i)
{
if (parent.Childs[i].Header == name)
parent.Childs.Remove(parent.Childs[i]);
}
}

public override string ToString()
{
return _Header;
}

#endregion
}
}

　　这个类实现了INotifyPropertyChanged接口，能够更好地实现前台数据刷新，并且只初始化得当，还可以直接往上追踪父结点，删除、添加子结点。

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