[WPF](小结4)TreeView的数据分层模板

前边研究的是某控件嵌套某控件,这里相当于树嵌套树,但这里不能这么叫,树很特殊,它有一个分层数据模板:HierarchicalDataTemplate,现在来看如何使用,

第一:选构建题目类,再建一个选项类,题目类集合中的每个项包含一个选项类集合,即数组嵌套数组,C#语句如下:

(为方便看清语句,类直接写在主程序中)

using System;
using System.Collections.Generic;
using System.Linq;
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.Navigation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;//ObservableCollection命名空间
namespace TreeviewWithHierarchical
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
        //题目类
        class question
        {
            public Int32 questionID//题目ID号
            { get; set; }
            public string questionName//题目名,比如:第1题或第2题等
            { get; set; }
            public ObservableCollection<choseItem> choseItems//某题中"选项类"的集合,比如A-D
            { get; set; }
            public question(Int32 _id, string _questionname, ObservableCollection<choseItem> _choseitems)//构造函数
            {
                questionID = _id;
                questionName = _questionname;
                choseItems = _choseitems;
            }
        }
        //选项类
        class choseItem
        {
            public string ChoseName//选项名,比如:A,B,C,D之类
            { get; set; }
            public string ChoseContent//选项内容
            { get; set; }
        }
        ObservableCollection<question> Questions = new ObservableCollection<question>();//题目数组
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            string[] CharStr = new string[4] { "A", "B", "C", "D" };
            for (int i = 0; i < 5; i++)
            {
                ObservableCollection<choseItem> ChoseItems = new ObservableCollection<choseItem>();//选项数组               
                for (int j = 0; j < 4; j++)
                {
                    choseItem item = new choseItem();//选项类
                    item.ChoseName = CharStr[j] + ":";
                    item.ChoseContent = "选项内容举例...";
                    ChoseItems.Add(item);
                }
                Questions.Add(new question(i, "__第" + (i + 1).ToString() + "题", ChoseItems));
            }
            treeview1.ItemsSource = Questions;
        }
    }
}

第二步:主界面的绑定语句如下:

<Window x:Class="TreeviewWithHierarchical.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="TreeviewWithHierarchical" Height="350" Width="525" Loaded="Window_Loaded">
    <Window.Resources >
        <!-- TreeView分层数据模板-->
        <HierarchicalDataTemplate ItemsSource="{Binding choseItems}" x:Key="myTreeviewWithHierarchical">
            <StackPanel Orientation="Horizontal" >
                <CheckBox Margin="3" IsChecked="False" />
                <Image Source="question2.png" Width="24" Height="24" />
                <TextBlock Margin="3" Text="{Binding questionName}" />
            </StackPanel>
            <HierarchicalDataTemplate.ItemTemplate >
                <DataTemplate >
                    <Border Margin="3" BorderBrush="Blue" BorderThickness="1" CornerRadius="3" >
                        <StackPanel Orientation="Horizontal" >
                            <TextBlock Margin="3" Text="选项名:" />
                            <TextBlock Margin="3" Text="{Binding ChoseName}" />
                            <TextBlock Margin="3" Text="内容:" />
                            <TextBlock Margin="3" Text="{Binding ChoseContent}" />
                        </StackPanel>
                    </Border>
                </DataTemplate>
            </HierarchicalDataTemplate.ItemTemplate>
        </HierarchicalDataTemplate>
    </Window.Resources>
   
    <Grid>
        <TreeView Name="treeview1" Margin="5" ItemTemplate="{StaticResource myTreeviewWithHierarchical}" />
    </Grid>
</Window>

第三:小结

1:TreeView可以使用分层数据模板HierarchicalDataTemplate,也可以不使用,根据不同的情况来进行选择

比如前边的例子直接操作TreeViewItem即可:

<DataTemplate  x:Key="myTreeViewGrid">
            <TreeViewItem Name="treeviewitem1" >
                <TreeViewItem.Header >
   ......
                </TreeViewItem.Header>
   ......
                <DataGrid ItemsSource="{Binding choseItems}"  >
                </DataGrid>
            </TreeViewItem>
</DataTemplate>

2:最简单的情形是直接使用TreeView的TreeViewItem作为节点,比如:

        <TreeView >
            <TreeViewItem Header="A">
                <TreeViewItem Header="a1" />
                <TreeViewItem Header="a2" />
            </TreeViewItem>
            <TreeViewItem Header="B">
                <TreeViewItem Header="b1" />
                <TreeViewItem Header="b2" />
            </TreeViewItem>
        </TreeView>