CODEWITHSUNDEEP
c#wpfdata-bindingtreeviewhierarchicaldatatemplate
Szwajcer
Szwajcer

Reputation: 11

Binding data onto a TreeView in WPF with one Model class

I need to show constants, which are based on other constants, in a TreeView but can't get it working. I already searched for an answer and tried to implement something similar to the tutorials I've found so far.

My aim is to show a TreeView (with dummy data for now) like this:

c1 (Parent)
     c3 (Child)
c2 (Parent)
     c4 (Child)
     c5 (Child)

My code looks like this (it's without the data I'm going to process later)

MainViewModel

{
  internal class MVM : INotifyPropertyChanged
  {
    public static ObservableCollection<Const> constants = new ObservableCollection<Const>();

    public event PropertyChangedEventHandler PropertyChanged;

    public MVM()
    {
      Const c1 = new Const("ABL", null);
      Const c2 = new Const("ASL", null);
      Const c3 = new Const("BBL", c1);
      Const c4 = new Const("BSL", c2);
      Const c5 = new Const("CBL", c2);


      constants.Add(c1);
      constants.Add(c2);

      c1.setChildren(new List<Const> { c3 });
      c2.setChildren(new List<Const> { c4, c5 });

      OnPropertyChange(nameof(constants));
    }

    protected void OnPropertyChange(string propertyName)
    {
      if (PropertyChanged != null)
      {
        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
      }
    }
  }
}

MainWindow.xaml header

<Window x:Class="ConstSearch.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:ConstSearch" 
        xmlns:vm="clr-namespace:ConstSearch"
        mc:Ignorable="d"
        Title="ConstSearch" Height="450" Width="450" MinHeight="450" MinWidth="450">
  <Window.DataContext>
    <vm:MVM/>
  </Window.DataContext>

MainWindow.xaml TreeView

<TreeView x:Name="constOutput"  Margin="25,76,25,0" Height="130" HorizontalAlignment="Stretch" VerticalAlignment="Top" ItemsSource="{Binding constants}"><!--Style="{StaticResource lightGrayTV}"-->
      <TreeView.ItemTemplate>
        <HierarchicalDataTemplate DataType="{x:Type local:Const}" ItemsSource="{Binding Children}">
          <TextBlock Text="{Binding Path=Name}"/>
          <HierarchicalDataTemplate.ItemTemplate>
            <HierarchicalDataTemplate DataType="{x:Type local:Const}" ItemsSource="{Binding Children}">
              <TextBlock Text="{Binding Path=Name}"/>
            </HierarchicalDataTemplate>
          </HierarchicalDataTemplate.ItemTemplate>
        </HierarchicalDataTemplate>
      </TreeView.ItemTemplate>
    </TreeView>

Const.cs Model

namespace ConstSearch
{
  class Const
  {
    public string Name { get; set; }
    public Const Parent { get; set; }
    public List<Const> Children { get; set; }

    public Const(string name, Const con)
    {
      Name = name;
      Parent = con;
    }

    public void setChildren(List<Const> children)
    {
      Children = children;
    }

    public override string ToString()
    {
      return $"Name: {Name}";
    }
  }
}

Thank you for your help in advance!

Upvotes: 0

Views: 157

Answers (1)

user2147873
user2147873

Reputation: 107

Everything seems fine from WPF and binding at first glance but the data.. which are fake if I get it...

      Const **c1** = new Const("ABL", null);
      Const c2 = new Const("ASL", null);
      Const *c3* = new Const("BBL", **c1**);
...
      **c1**.setChildren(new List<Const> { *c3* });

this is not tree as it has cycles, was this your intention? AFAK Hierarchical structures are about trees not graph, this can unfold for eternity or at least what meaning does it really have.

give a try without cycles in your test data

Upvotes: -1

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