TreeView —WPF—MVVM—HierarchicalDataTemplate详解编程语言

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、Model

using 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、ViewModel

using 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 
{ 
public class DistrictNodeViewModel : ModelCommon.NotifyObject 
{ 
private bool? isSelected = false; 
public bool? IsSelected 
{ 
get { return isSelected; } 
set 
{ 
isSelected = value; 
RaisePropertyChanged("IsSelected"); 
} 
} 
private bool? isChecked = false; 
public bool? IsChecked 
{ 
get { return isChecked; } 
set 
{ 
SetIsChecked(value); 
} 
} 
private void 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 in this.Children) 
{ 
if (value!=null) 
{ 
item.IsChecked = value; 
}                     
} 
} 
if (this.parent != null) 
{ 
if (this.Parent.Children.Count == this.Parent.Children.Count(item => item.isChecked == value)) 
{ 
//同一级节点全部选中，则父节点选中。反之亦然。 
this.Parent.IsChecked = value; 
} 
else if (this.Parent.Children.Count > this.Parent.Children.Count(item => item.isChecked == value)) 
{ 
if (this.Parent.IsChecked!=null) 
{ 
this.Parent.IsChecked = null; 
}                     
}                 
} 
} 
private bool? isExpand = false; 
public bool? IsExpand 
{ 
get { return isExpand; } 
set 
{ 
isExpand = value; 
RaisePropertyChanged("IsExpand"); 
} 
} 
private BitmapImage img; 
public BitmapImage Img 
{ 
get { return img; } 
set 
{ 
img = value; 
RaisePropertyChanged("Img"); 
} 
} 
private ObservableCollection<DistrictNodeViewModel> children = new ObservableCollection<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 
{ 
public class 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 DistrictNodeViewModel LoadData() 
{ 
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); 
DistrictNodeViewModel dnv = new DistrictNodeViewModel(); 
dnv.District = rootNodes[0]; 
SetDNV(dnv, rootNodes[0]); 
return dnv; 
} 
private void SetDNV(DistrictNodeViewModel vm,District root) 
{ 
if (root==null||root.Children==null||root.Children.Count==0) 
{ 
return; 
} 
foreach (var item in root.Children) 
{ 
DistrictNodeViewModel vmNew = 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="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
Title="MainWindow" Height="350" Width="525"> 
<Window.Resources> 
<HierarchicalDataTemplate x:Key="treeTemplate" ItemsSource="{Binding Children}"> 
<StackPanel Orientation="Horizontal"> 
<CheckBox IsChecked="{Binding IsChecked}"></CheckBox> 
<Image Source="{Binding Img}" Height="20" Width="16"></Image> 
<TextBlock Text="{Binding District.Xzqhmc}"></TextBlock> 
</StackPanel> 
</HierarchicalDataTemplate> 
</Window.Resources> 
<Grid> 
<TreeView  ItemTemplate="{StaticResource treeTemplate}" ItemsSource="{Binding VmNodes}"> 
</TreeView> 
</Grid> 
</Window>

　　二、效果

原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/13172.html

TreeView —WPF—MVVM—HierarchicalDataTemplate详解编程语言

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