采用HierarchicalDataTemplate数据模板和treeview在MVVM模式下实现行政区划树

摘要：采用HierarchicalDataTemplate数据模板和treeview在MVVM模式下实现行政区划树，支持勾选。

勾选父节点，子节点回全部自动勾选；子节点部分勾选时，父节点半勾选；子节点全部勾选时，父节点勾选。

反之亦然。

HierarchicalDataTemplate是分层数据模板，通常用于tree，menu等层级控件。

HierarchicalDataTemplate的ItemsSource属性绑定下一级数据源。

Model为行政区数据实体类，通常访问数据库获取数据并构建对象。

ViewModel为界面的抽象模型，表示界面的数据和行为，是Model和View的桥梁。

view就是界面。

一、代码1、Modelusing System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace WpfHierarchicalTemplate{public class District{public int ID { get; set; }public string Xzqhdm { get; set; }//行政区划代码public string Xzqhmc { get; set; }//行政区划名称public int Level { get; set; }//级别，0全国，1省，2地市，3县，4，乡镇，5，村public IList<District> Children { get; set; }public District Parent { get; set; }}}2、ViewModelusing System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Collections.ObjectModel;using System.Windows.Media;using System.Windows.Media.Imaging;namespace WpfHierarchicalTemplate{publicclass DistrictNodeViewModel :ModelCommon.NotifyObject{privatebool? isSelected = false;publicbool? IsSelected{get{ return isSelected; }set{isSelected = value;RaisePropertyChanged("IsSelected");}}privatebool? isChecked = false;publicbool? IsChecked{get{ return isChecked; }set{SetIsChecked(value);}}privatevoid SetIsChecked(bool? value){if (value != isChecked){isChecked = value;RaisePropertyChanged("IsChecked");}if (this.Children.Count>0&&this.Children[0].isChecked != value){//设置子节点勾选状态foreach (var item inthis.Children){if (value!=null){item.IsChecked = value;}}}if (this.parent != null){if (this.Parent.Children.Count == this.Parent.Children.Count(item =>item.is Checked == value)){//同一级节点全部选中，则父节点选中。

反之亦然。

this.Parent.IsChecked = value;}elseif (this.Parent.Children.Count>this.Parent.Children.Count(item =>item.i sChecked == value)){if (this.Parent.IsChecked!=null){this.Parent.IsChecked = null;}}}}privatebool? isExpand = false;publicbool? IsExpand{get{ return isExpand; }set{isExpand = value;RaisePropertyChanged("IsExpand");}}private BitmapImageimg;public BitmapImageImg{get{ return img; }set{img = value;RaisePropertyChanged("Img");}}private ObservableCollection<DistrictNodeViewModel> children = new Observable Collection<DistrictNodeViewModel>();public ObservableCollection<DistrictNodeViewModel> Children{get{ return children; }set{children = value;RaisePropertyChanged("Children");}}private DistrictNodeViewModel parent;public DistrictNodeViewModel Parent{get{ return parent; }set{parent = value;RaisePropertyChanged("Parent");}}private District district;public District District{get{ return district; }set{district = value;RaisePropertyChanged("District");}}}}using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Collections.ObjectModel;namespace WpfHierarchicalTemplate{publicclass DistrictMainViewModel :ModelCommon.NotifyObject{private ObservableCollection<DistrictNodeViewModel>vmNodes;public ObservableCollection<DistrictNodeViewModel>VmNodes{get{ return vmNodes; }set{vmNodes = value;RaisePropertyChanged("VmNodes");}}public DistrictMainViewModel(){this.VmNodes = new ObservableCollection<DistrictNodeViewModel> {LoadData()};}public DistrictNodeViewModelLoadData(){ObservableCollection<District>rootNodes =new ObservableCollection<District> ();District d00 = new District(){Xzqhmc = "全国",Parent = null};District d0 = new District(){Xzqhmc="河南",Parent=d00};District d1 = new District(){Xzqhmc = "北京",Parent = d00};District d2 = new District(){Xzqhmc = "山东",Parent = d00};District d11 = new District(){Xzqhmc = "海淀区",Parent = d1};District d12 = new District(){Xzqhmc = "石景山区",Parent = d1};District d13 = new District(){Xzqhmc = "朝阳区",Parent = d1};District d01 = new District(){Xzqhmc = "商丘",Parent = d0};District d02 = new District(){Xzqhmc = "郑州",Parent = d0};District d03 = new District(){Xzqhmc = "周口",Parent = d0};d1.Children = new List<District> { d11, d12, d13 }; d0.Children = new List<District> { d01, d02, d03 }; d00.Children = new List<District>{d1,d2,d0}; rootNodes.Add(d00);DistrictNodeViewModeldnv = new DistrictNodeViewModel();dnv.District = rootNodes[0];SetDNV(dnv, rootNodes[0]);return dnv;}privatevoid SetDNV(DistrictNodeViewModelvm,District root){if (root==null||root.Children==null||root.Children.Count==0){return;}foreach (var item in root.Children){DistrictNodeViewModelvmNew = new DistrictNodeViewModel();vmNew.District = item;vmNew.Parent = vm;vmNew.Img = new System.Windows.Media.Imaging.BitmapImage(new Uri("/dog.jpg", UriKind.Relative));vm.Children.Add(vmNew);SetDNV(vmNew, item);}}}}3、主窗口using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;namespace WpfHierarchicalTemplate{/// <summary>/// MainWindow.xaml的交互逻辑/// </summary>public partial class MainWindow : Window{public MainWindow(){InitializeComponent();this.DataContext = new DistrictMainViewModel();}}}4、前台xaml<Window x:Class="WpfHierarchicalTemplate.MainWindow"xmlns="/winfx/2006/xaml/presentation" xmlns:x="/winfx/2006/xaml"Title="MainWindow" Height="350" Width="525"><Window.Resources><HierarchicalDataTemplatex:Key="treeTemplate"ItemsSource="{Binding Childre n}"><StackPanel Orientation="Horizontal"><CheckBoxIsChecked="{Binding IsChecked}"></CheckBox><Image Source="{Binding Img}" Height="20" Width="16"></Image><TextBlock Text="{Binding District.Xzqhmc}"></TextBlock></StackPanel></HierarchicalDataTemplate></Window.Resources><Grid><TreeViewItemTemplate="{StaticResourcetreeTemplate}"ItemsSource="{Binding VmNodes}"></TreeView></Grid></Window>二、效果。