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WPF 中的treeview怎样代码展开指定的点呢。

问题

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<Window x:Class="DataBinding.BoundTreeView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="BoundTreeView" Height="300" Width="300"
    xmlns:data="clr-namespace:StoreDatabase;assembly=StoreDatabase"
    >
  <Window.Resources>
    <HierarchicalDataTemplate DataType="{x:Type data:Category}"
                                ItemsSource="{Binding Path=Products}">
      <TextBlock Text="{Binding Path=CategoryName}"/>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="{x:Type data:Product}"      >
      <TextBlock Text="{Binding Path=ModelName}" />      
    </HierarchicalDataTemplate>
    
  </Window.Resources>
  <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="auto"/>
            <ColumnDefinition Width="auto"/>
        </Grid.ColumnDefinitions>  
        <TreeView Name="treeCategories" Margin="5">
      
        </TreeView>
        <Button Width="40" Height="20" Grid.Column="1" Click="Button_Click"></Button>
  </Grid>
</Window>

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;

namespace DataBinding
{
    /// <summary>
    /// Interaction logic for BoundTreeView.xaml
    /// </summary>

    public partial class BoundTreeView : System.Windows.Window
    {

        public BoundTreeView()
        {
            InitializeComponent();

            treeCategories.ItemsSource = App.StoreDb.GetCategoriesAndProducts();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            
        
        }
    }
}

我希望点击右边的按钮能够展开指定的树节点，用的是HierarchicalDataTemplate的方式，就不知道咋做了。

已编辑彭123 2019年8月2日 9:54

2019年8月2日 9:53

答案

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代码是在WPF-Sample中HierarchicalDataTemplate上直接修改而成

修改xaml

    <DockPanel>
        <DockPanel.Resources>
            <local:ListLeagueList x:Key="MyList"/>

            <HierarchicalDataTemplate DataType    = "{x:Type local:League}"
                                ItemsSource = "{Binding Path=Divisions}">
                <TextBlock Text="{Binding Path=Name}"/>
            </HierarchicalDataTemplate>

            <HierarchicalDataTemplate DataType    = "{x:Type local:Division}"
                                ItemsSource = "{Binding Path=Teams}">
                <TextBlock Text="{Binding Path=Name}"/>
            </HierarchicalDataTemplate>

            <DataTemplate DataType="{x:Type local:Team}">
                <TextBlock Text="{Binding Path=Name}"/>
            </DataTemplate>
        </DockPanel.Resources>

        <Menu Name="menu1" DockPanel.Dock="Top" Margin="10,10,10,10">
            <MenuItem Header="My Soccer Leagues"
                  ItemsSource="{Binding Source={StaticResource MyList}}" />
        </Menu>

        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="auto"/>
                <RowDefinition Height="*"/>
            </Grid.RowDefinitions>
            <StackPanel Orientation="Horizontal">
                <TextBox Width="50" x:Name="serach"/>
                <Button Content="搜索" x:Name="S_btn" Click="S_btn_Click"/>
            </StackPanel>
            <TreeView x:Name="TV" Grid.Row="1">
                <TreeView.ItemContainerStyle>
                    <Style TargetType="TreeViewItem">
                        <Setter Property="IsExpanded" Value="{Binding  IsItemOpen,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
                        <Style.Triggers>
                            <Trigger Property="IsExpanded" Value="true">
                                <Setter Property="Background" Value="Red"/>
                            </Trigger>
                        </Style.Triggers>
                    </Style>
                </TreeView.ItemContainerStyle>
            </TreeView>
        </Grid>

    </DockPanel>

在定义的集合中编写一个bool值作为TreeViewItem是否展开的判断

添加类IsOpen

   public class IsOpen : INotifyPropertyChanged
    {
        protected void OnPropertyChanged([CallerMemberName] string name = "")
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
        }
        public event PropertyChangedEventHandler PropertyChanged;
        private bool _isopen;
        public bool IsItemOpen { get => _isopen; set { _isopen = value; OnPropertyChanged(); } }
    }

并让Division，League,Team均继承IsOpen

关键是编写TreeView的ItemContainerStyle

 <TreeView.ItemContainerStyle>
                    <Style TargetType="TreeViewItem">
                        <Setter Property="IsExpanded" Value="{Binding  IsItemOpen,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
                     </Style>
 </TreeView.ItemContainerStyle>

之后就是编写查找相关数据的节点，并修改IsItemOpen

 private void OpenExpandAtLastIndexName(string Name)
        {
            var item = from p in leagues
                       from c in p.Divisions
                       from o in c.Teams
                       where o.Name.Equals(Name)
                       select c;

            var p1 = item.ToList();

            foreach (var q in p1)
            {
                q.IsItemOpen = true;
                var b = leagues.FindAll(y => y.Divisions.FindAll(h => h.Equals(q)) != null);
                foreach (var g in b)
                {  
                    var f = g.Divisions.FindAll(h => h.Equals(q));
                    foreach (var r in f)
                    {
                        var bs= g.Divisions.Find(s => s.Equals(r));
                        if (bs != null)
                            g.IsItemOpen = true;
                    }
                }
            }
        }

其他cs部分：

     ListLeagueList leagues = new ListLeagueList();
        public MainWindow()
        {
            InitializeComponent();
           
            TV.ItemsSource = leagues;
            
        }

button代码

 private void S_btn_Click(object sender, RoutedEventArgs e)
        {
            OpenExpandAtLastIndexName(serach.Text);
        }

已编辑 ARM830 2019年8月3日 3:01
已标记为答案彭123 2019年8月4日 15:44

2019年8月3日 2:55

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WPF 中的treeview怎样代码展开指定的点呢。

问题

答案