I try to learn using treeview base one MVVM. I refer this tutorial https://www.codeproject.com/Articles/26288/Simplifying-the-WPF-TreeView-by-Using-the-ViewMode
It's very helpful and I try to understand it by rewrite code
TreeViewViewModel.cs
public class TreeViewViewModel
{
private ObservableCollection<TreeNode> _firstNode;
public static TreeNode _seletectedNode;
private ObservableCollection<TreeNode> _node;
private ICommand _addCommand;
public TreeViewViewModel(TreeNode rootNode) : this(rootNode, null) {}
public TreeViewViewModel(TreeNode rootNode, TreeViewViewModel parentNode)
{
_firstNode = new ObservableCollection<TreeNode>(rootNode.Node);
_node = new ObservableCollection<TreeNode>((from child in rootNode.Node select child).ToList<TreeNode>());
_addCommand = new AddCommand(this);
}
public ObservableCollection<TreeNode> FirstNode
{
get { return _firstNode; }
set { _firstNode = value; }
}
public ObservableCollection<TreeNode> Node
{
get { return _node; }
set { _node = value; }
}
public TreeNode Selected
{
get{ return _seletectedNode; }
set{ _seletectedNode = value;}
}
public ICommand AddCommand
{
get { return _addCommand; }
}
}
TreeNode.cs
public class TreeNode : INotifyPropertyChanged
{
private ObservableCollection<TreeNode> _Node = new ObservableCollection<TreeNode>();
private string _Name;
private string _ID;
private bool _isExpanded;
private bool _isSelected;
public ObservableCollection<TreeNode> Node
{
get { return _Node; }
set
{
_Node = value;
OnPropertyChanged("Node");
}
}
public string Name
{
get { return _Name; }
set { _Name = value; OnPropertyChanged("Name"); }
}
public string ID
{
get { return _ID; }
set { _ID = value; OnPropertyChanged("ID");}
}
public bool IsExpanded
{
get { return _isExpanded; }
set
{
if (value != _isExpanded)
{
_isExpanded = value;
this.OnPropertyChanged("IsExpanded");
}
}
}
public bool IsSelected
{
get { return _isSelected; }
set
{
if (value != _isSelected)
{
_isSelected = value;
this.OnPropertyChanged("IsSelected");
if (_isSelected) {TreeViewViewModel._seletectedNode = this;}
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
AddCommand.cs
public class AddCommand : ICommand
{
private TreeViewViewModel _TreeView;
public AddCommand(TreeViewViewModel treeView)
{
_TreeView = treeView;
}
public event EventHandler CanExecuteChanged;
public bool CanExecute(object parameter)
{
return true;
}
public void Execute(object parameter)
{
//Show Selected item
//MessageBox.Show(_TreeView.Selected.Name);
//Add first level item
//_TreeView.FirstNode.Add(new TreeNode { Name = "Hihi" });
//Rename selected item
//_TreeView.Selected.Name = "Hello";
//Remove first level item
//_TreeView.FirstNode.Remove(_TreeView.Selected);
//Add selected item
//_TreeView.Selected.Node.Add(new TreeNode { Name = "Hihi" });
}
}
MainWindown.xaml.cs
public partial class MainWindow : Window
{
public TreeViewViewModel _TreeView;
public MainWindow()
{
InitializeComponent();
TreeNode rootNode = new TreeNode
{
Name = "David",
Node =
{
new TreeNode
{
Name = "Alberto",
Node =
{
new TreeNode
{
Name = "Zena",
Node =
{
new TreeNode
{
Name = "Nick",
}
}
},
new TreeNode
{
Name = "Sarah",
},
}
},
new TreeNode
{
Name = "Komrade",
}
}
};
_TreeView = new TreeViewViewModel(rootNode);
base.DataContext = _TreeView;
}
}
MainWindow.xaml
<Window x:Class="TreeviewMVVM_Test.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:TreeviewMVVM_Test"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<TextBox Margin="10,35,380,260"/>
<Button Margin="154,27,324,268" Command="{Binding AddCommand}" />
<TreeView x:Name="treeView"
ItemsSource="{Binding FirstNode}"
BorderThickness="0"
Height="Auto" Width="Auto"
Margin="21,84,349,19">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}" BasedOn="{StaticResource {x:Type TreeViewItem}}">
<Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />
<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
<Setter Property="FontWeight" Value="Normal" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="FontWeight" Value="Bold" />
</Trigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Node}">
<TextBlock Text="{Binding Name}" />
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</Grid>
</Window>
My source code is working fine, I can add childnode from selected node, remove first level node, rename selected node, get selected node. But only 1 thing, I don't know how to store and get parent's node
I read thought out the Josh tutorial, it's seem to be parent node is stored in contructor. Here below is Josh's code. If i use like that Parent node is a TreeViewViewModel, not a node. I don't want like that, Is there any way to make parent node to TreeNode type. I want to use like this _treeView.Seletect.Parent.Name and it's should print parent name of selected node.
private PersonViewModel(Person person, PersonViewModel parent)
{
_person = person;
_parent = parent;
_children = new ObservableCollection<PersonViewModel>(
(from child in _person.Children
select new PersonViewModel(child, this))
.ToList<PersonViewModel>());
}
