HOW TO TRAVERSE PARENT NODES USING BUTTONS

[Rahul Makwana]

I am trying to achieve following : 

• Parent 1
• Parent 2
• Parent 3
• Parent 4

if current selected Node is Parent1 and user presses Next Button I want Parent2 node to be selected node. How do I achieve this using MVVM ? 

Thanks

[Vijayalakshmi Roopkumar]

Hi Rahul,

Thank you for contacting Syncfusion Support.

We have prepared the sample that tries to meet your requirement. In our sample, we have added the items using the MVVM pattern and also change the SelectedTreeItem based on user need. Please find the code example for the same from below: 

XAML: 

 

<syncfusion:TreeViewAdv x:Name="TreeViewone"  ItemsSource="{Binding TreeItems}" SelectedTreeItem="{Binding SelectedTreeItem, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" Grid.Row="0"> 

 

<syncfusion:TreeViewAdv.ItemTemplate> 

 

<HierarchicalDataTemplate ItemsSource="{Binding SubItems}"> 

 

<TextBlock Text="{Binding Header}" /> 

 

</HierarchicalDataTemplate> 

 

</syncfusion:TreeViewAdv.ItemTemplate> 

 

</syncfusion:TreeViewAdv> 

 

 

 

C#: 

 

public class ViewModel : INotifyPropertyChanged 

{ 

public commandclass TraverseSelectedTreeItem { get; set; } 

public ViewModel() 

 

{ 

 

TreeItems = new ObservableCollection<Model>(); 

 

PopulateData(); 

//Intialize the command 

this.TraverseSelectedTreeItem = new commandclass(CanTraverseSelectedTreeItem, ExecuteTraverseSelectedTreeItem); 

 

 

} 

 

//Execute when the button clicks 

private void ExecuteTraverseSelectedTreeItem(object obj) 

{ 

TreeViewAdv item = obj as TreeViewAdv; 

 

if (item.SelectedTreeItem == TreeItems[0]) 

{ 

item.ClearSelection(); 

item.SelectedTreeItem = TreeItems[1]; 

} 

 

 

} 

 

private bool CanTraverseSelectedTreeItem(object obj) 

{ 

return true; 

} 

 

 

private object selectedtreeitem; 

public object SelectedTreeItem 

{ 

get 

{ 

return selectedtreeitem; 

} 

set 

{ 

selectedtreeitem = value; 

NotifyPropertyChanged("SelectedTreeItem"); 

 

 

 

} 

} 

public ObservableCollection<Model> TreeItems { get; set; } 

 

 

//Used to populate the items 

private void PopulateData() 

 

{ 

 

Model Root1 = new Model() { Header = "Parent1" }; 

 

PopulateSubItems(Root1); 

 

TreeItems.Add(Root1); 

 

Model Root2 = new Model() { Header = "Parent2" }; 

 

PopulateSubItems(Root2); 

 

TreeItems.Add(Root2); 

 

Model Root3 = new Model() { Header = "Parent3" }; 

 

PopulateSubItems(Root3); 

 

TreeItems.Add(Root3); 

 

Model Root4 = new Model() { Header = "Parent4" }; 

 

PopulateSubItems(Root4); 

 

TreeItems.Add(Root3); 

 

Model Root5 = new Model() { Header = "Parent5" }; 

 

PopulateSubItems(Root5); 

 

TreeItems.Add(Root3); 

 

} 

 

//Used the Populate the subitems 

private void PopulateSubItems(Model Root) 

 

{ 

 

Model SubItem1 = new Model() { Header = Root.Header + " Item1" }; 

 

Model SubItem2 = new Model() { Header = Root.Header + " Item2" }; 

 

Model SubItem3 = new Model() { Header = Root.Header + " Item3" }; 

 

Model SubItem4 = new Model() { Header = Root.Header + " Item4" }; 

 

Root.SubItems.Add(SubItem1); 

 

Root.SubItems.Add(SubItem2); 

 

Root.SubItems.Add(SubItem3); 

 

Root.SubItems.Add(SubItem4); 

 

} 

 

//INotifyPropertyChanged 

public event PropertyChangedEventHandler PropertyChanged; 

private void NotifyPropertyChanged(String info) 

{ 

if (PropertyChanged != null) 

{ 

PropertyChanged(this, new PropertyChangedEventArgs(info)); 

} 

} 

 

} 

 

 

Sample: http://www.syncfusion.com/downloads/support/directtrac/185723/ze/TreeViewTraverse1549970059

Video: http://www.syncfusion.com/downloads/support/directtrac/185723/ze/Traverse761658605 

Please try this solution and let us know if it is helpful

Regards,
Vijayalakshmi V.R.