Mark Tree node expandable


   
    
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      HorizontalAlignment="Center" VerticalAlignment="Center">

<TreeView>
  <TreeViewItem Header="A" IsExpanded="True">
    <TreeViewItem Header="B" />
    <TreeViewItem Header="C" IsExpanded="True">
      <TreeViewItem Header="D" />
      <TreeViewItem Header="E" />
    </TreeViewItem>
    <TreeViewItem Header="F" />
  </TreeViewItem>
  <TreeViewItem IsExpanded="True">
    <TreeViewItem.Header>
      <StackPanel Orientation="Horizontal">
        <Ellipse Fill="Blue" Width="15" Height="15" />
        <TextBlock Text="Third top-level item" />
        <Ellipse Fill="Blue" Width="15" Height="15" />
      </StackPanel>
    </TreeViewItem.Header>
    <TreeViewItem Header="Child a" />
    <TreeViewItem Header="Child b" />
    <TreeViewItem Header="Child c" />
  </TreeViewItem>
</TreeView>
</Page>

   
    
    
    
     


Bind a TreeView to a data source and use DataTemplate objects to customize the TreeView.


   
  


<Window x:Class="TreeViewDataBinding.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="TreeViewDataBinding"
    xmlns:EngNews="clr-namespace:TreeViewDataBinding">

  <Window.Resources>
    <ObjectDataProvider x:Key="EasternHemisphereDataSource" ObjectType="{x:Type EngNews:WebSiteGroupA}"/>
    <ObjectDataProvider x:Key="WesternHemisphereDataSource" ObjectType="{x:Type EngNews:WebSiteGroupB}"/>
    <DataTemplate x:Key="NewspaperTVItem">
      <DockPanel>
        <Image Source="c:image.jpg"/>
        <TextBlock VerticalAlignment="center" Text ="{Binding Path=Name}"/>
      </DockPanel>
    </DataTemplate>
    <DataTemplate x:Key="WesternHemisphereHeaderTemplate">
      <DockPanel>
        <Ellipse Width="7" Height="7"  Fill="Blue" DockPanel.Dock="Left"/>
        <TextBlock Margin="2,0,0,0" VerticalAlignment="Center" DockPanel.Dock="Right">
          test
        </TextBlock>
      </DockPanel>
    </DataTemplate>
    <DataTemplate x:Key="EasternHemisphereHeaderTemplate">
      <DockPanel>
        <Ellipse Width="7" Height="7"  Fill="Blue" DockPanel.Dock="Left"/>
        <TextBlock DockPanel.Dock="Right">Eastern Hemisphere</TextBlock>
      </DockPanel>
    </DataTemplate>
  </Window.Resources>
  <StackPanel>
      <TreeView Name="WebSiteEntrys" SelectedItemChanged="SelectedNewspaperChanged">
        <TreeViewItem HeaderTemplate="{StaticResource WesternHemisphereHeaderTemplate}" 
                      ItemsSource="{Binding Source={StaticResource WesternHemisphereDataSource}}"
                      ItemTemplate="{StaticResource NewspaperTVItem}"/>
        <TreeViewItem HeaderTemplate="{StaticResource EasternHemisphereHeaderTemplate}"
                      ItemsSource="{Binding Source={StaticResource EasternHemisphereDataSource}}"
                      ItemTemplate="{StaticResource NewspaperTVItem}"/>
      </TreeView>
    <Frame Name = "NewspaperFrame" Content="this is a test."/>
  </StackPanel>
</Window>
//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Shapes;
using System.Collections.ObjectModel;

namespace TreeViewDataBinding
{
    public partial class Window1 : Window{
        public Window1(){
            InitializeComponent();
        }
        private void SelectedNewspaperChanged(object sender,RoutedPropertyChangedEventArgs<Object> e){
            WebSiteEntry engnews = WebSiteEntrys.SelectedItem as WebSiteEntry;
            if( engnews != null ) NewspaperFrame.Navigate(new System.Uri(engnews.Website));
        }
    }
    public class WebSiteEntry{
        private string _name;
        private string _website;

        public string Website
        {
            get { return _website; }
            set { _website = value; }
        }

        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }

        public WebSiteEntry(string name, string website)
        {
            Name = name;
            Website = website;
        }
    }
    public class WebSiteGroupA : ObservableCollection<WebSiteEntry>
    {
        public WebSiteGroupA()
        {
            Add(new WebSiteEntry("A","http://www.A.com"));
            Add(new WebSiteEntry("B","http://www.B.com"));
            Add(new WebSiteEntry("C","http://www.C.com"));
        }
    }

    public class WebSiteGroupB : ObservableCollection<WebSiteEntry>
    {
        public WebSiteGroupB()
        {
            Add(new WebSiteEntry("D","http://www.D.com/"));
            Add(new WebSiteEntry("E","http://www.E.net/"));
            Add(new WebSiteEntry("F","http://www.F.com"));
        }
    }
}

   
    
     


Handles the Selected event for all TreeViewItems


   
  
<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF" Height="200" Width="300">
    <DockPanel LastChildFill="True">
        <DockPanel.Resources>
            <Style TargetType="{x:Type TreeViewItem}">
                <EventSetter Event="Selected" Handler="TreeViewItem_Selected" />
            </Style>
        </DockPanel.Resources>
        <Button Click="Button_Click" DockPanel.Dock="Bottom" Content="Show Selected" MaxHeight="23" MaxWidth="100" />
        <TreeView FontSize="16" Name="tvTree">
            <TreeViewItem Header="A" IsExpanded="True">
                <TreeViewItem Header="1">
                    <TreeViewItem Header="2" />
                    <TreeViewItem Header="3" />
                </TreeViewItem>
                <TreeViewItem Header="B" IsExpanded="True">
                    <TreeViewItem Header="11" />
                    <TreeViewItem Header="22" />
                </TreeViewItem>
            </TreeViewItem>
            <TreeViewItem Header="C">
                <TreeViewItem Header="E">
                    <TreeViewItem Header="111" />
                    <TreeViewItem Header="222" />
                    <TreeViewItem Header="333" />
                </TreeViewItem>
                <TreeViewItem Header="F">
                    <TreeViewItem Header="1111" />
                    <TreeViewItem Header="2222" />
                    <TreeViewItem Header="333" />
                </TreeViewItem>
            </TreeViewItem>
        </TreeView>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Controls;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }
        private void TreeViewItem_Selected(object sender, RoutedEventArgs e)
        {
            TreeViewItem item = sender as TreeViewItem;
            if (item == e.OriginalSource)
            {
                Console.WriteLine(item.Header);
                Console.WriteLine(item.Items.Count);
            }
            else
            {
                Console.WriteLine("Parent of selected");
                Console.WriteLine(item.Header);
                Console.WriteLine(item.Items.Count);
            }
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            TreeViewItem item = tvTree.SelectedItem as TreeViewItem;

            if (item != null)
            {
                MessageBox.Show("Item selected: " + item.Header, Title);
            }
            else
            {
                MessageBox.Show("No item selected", Title);
            }
        }
    }
}

   
    
     


Set TreeView with TreeViewItem


   
  
<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF" Height="200" Width="300">
    <DockPanel LastChildFill="True">
        <DockPanel.Resources>
            <Style TargetType="{x:Type TreeViewItem}">
                <EventSetter Event="Selected" Handler="TreeViewItem_Selected" />
            </Style>
        </DockPanel.Resources>
        <Button Click="Button_Click" DockPanel.Dock="Bottom" Content="Show Selected" MaxHeight="23" MaxWidth="100" />
        <TreeView FontSize="16" Name="tvTree">
            <TreeViewItem Header="A" IsExpanded="True">
                <TreeViewItem Header="1">
                    <TreeViewItem Header="2" />
                    <TreeViewItem Header="3" />
                </TreeViewItem>
                <TreeViewItem Header="B" IsExpanded="True">
                    <TreeViewItem Header="11" />
                    <TreeViewItem Header="22" />
                </TreeViewItem>
            </TreeViewItem>
            <TreeViewItem Header="C">
                <TreeViewItem Header="E">
                    <TreeViewItem Header="111" />
                    <TreeViewItem Header="222" />
                    <TreeViewItem Header="333" />
                </TreeViewItem>
                <TreeViewItem Header="F">
                    <TreeViewItem Header="1111" />
                    <TreeViewItem Header="2222" />
                    <TreeViewItem Header="333" />
                </TreeViewItem>
            </TreeViewItem>
        </TreeView>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Controls;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }
        private void TreeViewItem_Selected(object sender, RoutedEventArgs e)
        {
            TreeViewItem item = sender as TreeViewItem;
            if (item == e.OriginalSource)
            {
                Console.WriteLine(item.Header);
                Console.WriteLine(item.Items.Count);
            }
            else
            {
                Console.WriteLine("Parent of selected");
                Console.WriteLine(item.Header);
                Console.WriteLine(item.Items.Count);
            }
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            TreeViewItem item = tvTree.SelectedItem as TreeViewItem;

            if (item != null)
            {
                MessageBox.Show("Item selected: " + item.Header, Title);
            }
            else
            {
                MessageBox.Show("No item selected", Title);
            }
        }
    }
}

   
    
     


Mark Tree node expandable


   
    
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      HorizontalAlignment="Center" VerticalAlignment="Center">

<TreeView>
  <TreeViewItem Header="A" IsExpanded="True">
    <TreeViewItem Header="B" />
    <TreeViewItem Header="C" IsExpanded="True">
      <TreeViewItem Header="D" />
      <TreeViewItem Header="E" />
    </TreeViewItem>
    <TreeViewItem Header="F" />
  </TreeViewItem>
  <TreeViewItem IsExpanded="True">
    <TreeViewItem.Header>
      <StackPanel Orientation="Horizontal">
        <Ellipse Fill="Blue" Width="15" Height="15" />
        <TextBlock Text="Third top-level item" />
        <Ellipse Fill="Blue" Width="15" Height="15" />
      </StackPanel>
    </TreeViewItem.Header>
    <TreeViewItem Header="Child a" />
    <TreeViewItem Header="Child b" />
    <TreeViewItem Header="Child c" />
  </TreeViewItem>
</TreeView>
</Page>

   
    
    
    
     


Create a Tree and add children


   
    

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      HorizontalAlignment="Center" VerticalAlignment="Center">

<TreeView>
  <TreeViewItem Header="A" IsExpanded="True">
    <TreeViewItem Header="B" />
    <TreeViewItem Header="C" IsExpanded="True">
      <TreeViewItem Header="D" />
      <TreeViewItem Header="E" />
    </TreeViewItem>
    <TreeViewItem Header="F" />
  </TreeViewItem>
  <TreeViewItem Header="G">
    <TreeViewItem Header="Child a" />
    <TreeViewItem Header="Child b" />
    <TreeViewItem Header="Child c" />
  </TreeViewItem>
</TreeView>
</Page>

   
    
    
    
     


ToolTip With Binding


   
  

<Window x:Class="WpfApplication1.Window1"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:local="clr-namespace:WpfApplication1" 
  Title="WithBinding" Height="135" Width="200">
  <Window.Resources>
    <local:Employee x:Key="Tom" Name="Tom" Age="11" />
    <local:AgeToForegroundConverter x:Key="ageConverter" />
    <local:Base16Converter x:Key="Base16Converter" />
  </Window.Resources>
  <StackPanel DataContext="{StaticResource Tom}">
    <TextBlock>Name:</TextBlock>
    <TextBox Text="{Binding Path=Name}" />
    <TextBox Text="{Binding Path=Name, Source={StaticResource Tom}}" />
    <TextBlock>Age:</TextBlock>
    <TextBox>
      <TextBox.Text>
        <Binding Path="Age" />
      </TextBox.Text>
    </TextBox>
    <TextBox Name="ageTextBox" Text="{Binding Path=Age}"
             Foreground="{Binding Path=Age, Converter={StaticResource ageConverter}}" />
    <TextBox Text="{Binding Path=Age, Converter={StaticResource Base16Converter}}"
             Foreground="{Binding Path=Age, Converter={StaticResource ageConverter}}" />
    <TextBox Name="ageTextBoxOneWay" Foreground="{Binding Path=Age, Mode=OneWay,Source={StaticResource Tom}, Converter={StaticResource ageConverter}}"
      ToolTip="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)&#91;0&#93;.ErrorContent}">
      <TextBox.Text>
        <Binding Path="Age" UpdateSourceTrigger="PropertyChanged">
          <Binding.ValidationRules>
            <local:NumberRangeRule Min="0" Max="128" />
          </Binding.ValidationRules>
        </Binding>
      </TextBox.Text>
    </TextBox>
    <Button Name="birthdayButton" Foreground="{Binding Path=Foreground, ElementName=ageTextBox}">Birthday</Button>
  </StackPanel>
</Window>
//File:Window.xaml.cs

using System;
using System.Collections.Generic;
using System.Text;
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.Shapes;
using System.ComponentModel;
using System.Diagnostics;


namespace WpfApplication1 {

  public class Employee : INotifyPropertyChanged {

    public event PropertyChangedEventHandler PropertyChanged;
    protected void Notify(string propName) {
      if( this.PropertyChanged != null ) {
        PropertyChanged(this, new PropertyChangedEventArgs(propName));
      }
    }

    string name;
    public string Name {
      get { return this.name; }
      set {
        this.name = value;
        Notify("Name");
      }
    }

    int age;
    public int Age {
      get { return this.age; }
      set {
        this.age = value;
        Notify("Age");
      }
    }

    public Employee() { }
    public Employee(string name, int age) {
      this.name = name;
      this.age = age;
    }
  }

  public partial class Window1 : Window {
    public Window1() {
      InitializeComponent();
      this.birthdayButton.Click += birthdayButton_Click;
    }
    void birthdayButton_Click(object sender, RoutedEventArgs e) {
      Employee emp = (Employee)this.FindResource("Tom");
      ++emp.Age;
      Console.WriteLine(emp.Name);
      Console.WriteLine(emp.Age);
    }
  }
  [ValueConversion(/* sourceType */ typeof(int), /* targetType */ typeof(Brush))]
  public class AgeToForegroundConverter : IValueConverter {
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
      if( targetType != typeof(Brush) ) { return null; }
      int age = int.Parse(value.ToString());
      return (age > 60 ? Brushes.Red : Brushes.Black);
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
      throw new NotImplementedException();
    }
  }

  public class Base16Converter : IValueConverter {
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
      return ((int)value).ToString("x");
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
      return int.Parse((string)value, System.Globalization.NumberStyles.HexNumber);
    }
  }

  public class NumberRangeRule : ValidationRule {
    int _min;
    public int Min {
      get { return _min; }
      set { _min = value; }
    }

    int _max;
    public int Max {
      get { return _max; }
      set { _max = value; }
    }

    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo) {
      int number;
      if( !int.TryParse((string)value, out number) ) {
        return new ValidationResult(false, "Invalid number format");
      }

      if( number < _min || number > _max ) {
        string s = string.Format("Number out of range ({0}-{1})", _min, _max);
        return new ValidationResult(false, s);
      }
      return ValidationResult.ValidResult;
    }
  }
}