DataTemplate简而言之，解决的就是后台代码中的类以怎么样的形式展现在xaml前台代码中的问题。
所以DataTemplate一般都要指定DataType，一般放在resource中，而HierarchicalDataTemplate是一种特殊的DataTemplate，
它指定一个ItemsSource，当自身属性是列表时，有次序的在前台展示下去。
以下是一个简单的Demo
<Window x:Class="EB_Func_DB.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:EB_Func_DB"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<HierarchicalDataTemplate DataType="{x:Type local:Module}"
ItemsSource="{Binding SubModules}">
<TextBlock Text="{Binding Path=Name}">
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="添加子模块" Click="MenuItem_Click_2" CommandParameter="{Binding}"/>
<MenuItem Header="删除模块" Click="MenuItem_Click_1" CommandParameter="{Binding}"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type local:SubModule}"
ItemsSource="{Binding PlugInFuncs}">
<TextBlock Text="{Binding Path=Name}">
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="添加功能" Click="MenuItem_Click_4" CommandParameter="{Binding}" />
<MenuItem Header="删除子模块" Click="MenuItem_Click_3" CommandParameter="{Binding}" />
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type local:PlugInFunc}">
<TextBlock Text="{Binding Path=FuncName}">
<TextBlock.ContextMenu>
<ContextMenu >
<MenuItem Header="添加功能" Click="MenuItem_Click_4" CommandParameter="{Binding}"/>
<MenuItem Header="删除功能" Click="MenuItem_Click_5" CommandParameter="{Binding}"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</HierarchicalDataTemplate>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="30"/>
<RowDefinition Height="30"/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition Height="30"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="80"/>
<ColumnDefinition Width="100"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="专业:" VerticalAlignment="Center" HorizontalAlignment="Center"/>
<ComboBox x:Name="majorComBox" Grid.Column="1" VerticalAlignment="Center" HorizontalAlignment="Center" Width="95" Margin="2"/>
</Grid>
<Grid Grid.Row="1">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="80"/>
<ColumnDefinition Width="200"/>
<ColumnDefinition Width="35"/>
<ColumnDefinition Width="45"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="插件路径:" VerticalAlignment="Center" HorizontalAlignment="Center"/>
<TextBlock Grid.Column="1" x:Name="pathTextBox" VerticalAlignment="Center" HorizontalAlignment="Center" Text="unselected" Foreground="Gray" Width="195" Margin="2"/>
<Button Grid.Column="2" x:Name="pathBtn" VerticalAlignment="Center" HorizontalAlignment="Center" Content="···" Click="pathBtn_Click" Width="30" Margin="2"/>
</Grid>
<DataGrid Grid.Row="2" x:Name="funcDataGrid" AutoGenerateColumns="False" CanUserAddRows="False"
CanUserDeleteRows="False" CanUserSortColumns="False" RowHeaderWidth="0"
MouseDoubleClick="funcDataGrid_MouseDoubleClick"
>
<DataGrid.ColumnHeaderStyle>
<Style TargetType="DataGridColumnHeader">
<Setter Property="HorizontalContentAlignment" Value="Center"></Setter>
<Setter Property="VerticalContentAlignment" Value="Center"></Setter>
</Style>
</DataGrid.ColumnHeaderStyle>
<DataGrid.Columns>
<DataGridCheckBoxColumn Header="是否加入数据库" Binding="{Binding Checked}">
</DataGridCheckBoxColumn>
<DataGridTextColumn Header="名称" Binding="{Binding Path=Name}" IsReadOnly="True">
</DataGridTextColumn>
<DataGridTextColumn Header="描述" Binding="{Binding Path=Describe}" IsReadOnly="True">
</DataGridTextColumn>
<DataGridTextColumn Header="是否在数据库" Binding="{Binding Path=Info}" IsReadOnly="True">
</DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
<TreeView Grid.Row="3" x:Name="treeView"
>
<TreeView.ItemContainerStyle>
<Style TargetType="TreeViewItem">
<Setter Property="IsExpanded" Value="True" />
</Style>
</TreeView.ItemContainerStyle>
<TreeView.ContextMenu>
<ContextMenu>
<MenuItem Header="增加模块" Click="MenuItem_Click"/>
</ContextMenu>
</TreeView.ContextMenu>
</TreeView>
<Button Grid.Row="4" x:Name="ok" Content="确定" Click="ok_Click"/>
</Grid>
</Window>