WPF日积月累之TreeView动态绑定

一、概述

本文演示了如何递归生成数据，用于绑定TreeView以及TreeItem的双击事件。

二、参考代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace BindingDemo6TreeBinding
{

    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            #region 用于绑定的数据
            List<TreeItem> grpLst = new List<TreeItem>(){
                new TreeItem(){ID=0,ItemName="Root", ParentId = -1,IsExpanded=true},//设置初始状态为展开状态

                new TreeItem(){ID=1,ItemName="Item1",ParentId=0},
                new TreeItem(){ID=2,ItemName="Item1-1",ParentId=1},
                new TreeItem(){ID=3,ItemName="Item1-2",ParentId=1},
                new TreeItem(){ID=4,ItemName="Item1-3",ParentId=1},

                new TreeItem(){ID=5,ItemName="Item1-3-1",ParentId=4},
                new TreeItem(){ID=6,ItemName="Item1-3-2",ParentId=4},



                new TreeItem(){ID=7,ItemName="Item2",ParentId=0},
                new TreeItem(){ID=8,ItemName="Item2-1",ParentId=7},
                new TreeItem(){ID=9,ItemName="Item2-2",ParentId=7},

                new TreeItem(){ID=10,ItemName="Item3",ParentId=0}
            };
            #endregion

            this.cmbGoup.ItemsSource = grpLst;//comboBox数据源
            this.cmbGoup.SelectedValuePath = "ID";
            this.cmbGoup.DisplayMemberPath = "ItemName";

            List<TreeItem> lstGroup = getTreeData(-1, grpLst);//初始化时获取父节点为-1的数据
            this.tvGroup.ItemsSource = lstGroup;//数据绑定
        }
        /// <summary>
        /// 递归生成树形数据
        /// </summary>
        /// <param name="delst"></param>
        /// <returns></returns>
        public List<TreeItem> getTreeData(int parentid, List<TreeItem> nodes)
        {
            List<TreeItem> mainNodes = nodes.Where(x => x.ParentId == parentid).ToList<TreeItem>();
            List<TreeItem> otherNodes = nodes.Where(x => x.ParentId != parentid).ToList<TreeItem>();
            foreach (TreeItem grp in mainNodes)
            {
                grp.ChildrenItems = getTreeData(grp.ID, otherNodes);
            }
            return mainNodes;
        }

        /// <summary>
        /// 下拉框关闭事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void cmbGoup_DropDownClosed(object sender, EventArgs e)
        {
            if (this.cmbGoup.SelectedValue == null)
            {
                return;
            }
            int groupId = (int)this.cmbGoup.SelectedValue;//选中的组号
            List<TreeItem> lstGroup = getTreeData(groupId, (List<TreeItem>)cmbGoup.ItemsSource);
            this.tvGroup.ItemsSource = lstGroup;
        }


        private void tvDomain_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            TreeViewItem trvItem = sender as TreeViewItem;
            if(trvItem.IsSelected)
            {
                TreeItem selectedItem = (TreeItem)(this.tvGroup.SelectedItem);
                MessageBox.Show(selectedItem.ItemName);
            }          
        }
    }
    public class TreeItem:ViewModelBase
    {
        public TreeItem()
        {
            this.ChildrenItems = new List<TreeItem>();
            this.ParentId = 0;//主节点的父id默认为0
        }

        public List<TreeItem> ChildrenItems { get; set; }
        public int ID { get; set; }//id
        public int ParentId { get; set; }//parentID
        public string ItemName { get; set; }

        private bool isExpanded;
        public bool IsExpanded { get { return isExpanded; } set { isExpanded = value;
                OnPropertyChanged(nameof(IsExpanded));
            } }


        private bool isSelected;
        public bool IsSelected
        {
            get { return isSelected; }
            set
            {
                isSelected = value;
                OnPropertyChanged(nameof(IsSelected));
            }
        }




    }
    public abstract class ViewModelBase : INotifyPropertyChanged, IDisposable
    {
        public virtual string DisplayName { get; set; }

        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }


        #region IDisposable Members

        public void Dispose()
        {
            this.OnDispose();

        }

        protected virtual void OnDispose()
        {
        }

        #endregion
    }
}

<Window x:Class="BindingDemo6TreeBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:BindingDemo6TreeBinding"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid >
        <Grid.RowDefinitions>
            <RowDefinition Height="81*"/>
            <RowDefinition Height="239*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="178*"/>
            <ColumnDefinition Width="339*"/>
        </Grid.ColumnDefinitions>
        <StackPanel Margin="10" Grid.ColumnSpan="2">
            <Label Content="选择组节点："></Label>
            <ComboBox MaxDropDownHeight="100" Name="cmbGoup" DropDownClosed="cmbGoup_DropDownClosed" ></ComboBox>
        </StackPanel>
        <StackPanel Margin ="10" Grid.Row="1">
            <TreeView x:Name="tvGroup" ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.HorizontalScrollBarVisibility="Auto">
                <TreeView.ItemContainerStyle>
                    <Style TargetType="{x:Type TreeViewItem}">
                        <Setter Property="IsExpanded" Value="{Binding IsExpanded,Mode=TwoWay}" />
                        <Setter Property="IsSelected" Value="{Binding IsSelected,Mode=TwoWay}"/>
                        <EventSetter Event="MouseDoubleClick" Handler="tvDomain_MouseDoubleClick"></EventSetter>
                    </Style>
                </TreeView.ItemContainerStyle>
                <TreeView.ItemTemplate>
                    <HierarchicalDataTemplate ItemsSource="{Binding ChildrenItems}">
                        <StackPanel>
                            <TextBlock VerticalAlignment="Center" FontSize="14" Text="{Binding ItemName}" Margin="2,0,0,0"></TextBlock>
                        </StackPanel>
                    </HierarchicalDataTemplate>
                </TreeView.ItemTemplate>
            </TreeView>
        </StackPanel>
        <GroupBox  Grid.Column="1" Grid.Row="1"  Margin="2" BorderThickness="0.6" BorderBrush="Silver">


            <Frame x:Name="mainFrame" Margin="2" ScrollViewer.CanContentScroll="True" NavigationUIVisibility="Hidden"  />

        </GroupBox>
    </Grid>
</Window>