How to do navigation on selection in Xamarin.Forms TreeView (SfTreeView)

You can navigate to another page by selecting the TreeViewNode in Xamarin.Forms SfTreeView by binding SelectedItem property from ViewModel.

XAML

Binding ViewModel TreeViewSelectedItem to SfTreeView.SelectedItem.

ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:TreeViewXamarin"
             xmlns:syncfusion="clr-namespace:Syncfusion.XForms.TreeView;assembly=Syncfusion.SfTreeView.XForms"
             x:Class="TreeViewXamarin.MainPage">
    <ContentPage.BindingContext>
        <local:FileManagerViewModel x:Name="viewModel"/>
    </ContentPage.BindingContext>
    <ContentPage.Content>
        <syncfusion:SfTreeView x:Name="treeView" ChildPropertyName="SubFiles" SelectedItem="{Binding TreeViewSelectedItem, Mode=TwoWay}" ExpandActionTarget="Node" ItemTemplateContextType="Node" AutoExpandMode="None" ItemsSource="{Binding ImageNodeInfo}">
            <syncfusion:SfTreeView.ItemTemplate>
                <DataTemplate>
                    <Grid x:Name="grid" RowSpacing="0" >
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="40" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <Image Source="{Binding Content.ImageIcon}" VerticalOptions="Center" HorizontalOptions="Center" HeightRequest="35" WidthRequest="35"/>
                        <Grid Grid.Column="1" RowSpacing="1" Padding="1,0,0,0" VerticalOptions="Center">
                            <Label LineBreakMode="NoWrap" Text="{Binding Content.ItemName}" VerticalTextAlignment="Center"/>
                        </Grid>
                    </Grid>
                </DataTemplate>
            </syncfusion:SfTreeView.ItemTemplate>
        </syncfusion:SfTreeView>
    </ContentPage.Content>
</ContentPage>

C#

Navigate to another page in the ViewModel TreeViewSelectedItem setter using PushAsync method.

namespace TreeViewXamarin
{
    public class FileManagerViewModel
    {
        private FileManager treeViewSelectedItem;

        public FileManager TreeViewSelectedItem
        {
            get { return treeViewSelectedItem; }
            set
            {
                if (treeViewSelectedItem != value)
                {
                    treeViewSelectedItem = value;
                    ItemSelected(treeViewSelectedItem);
                }
            }
        }

        private async void ItemSelected(FileManager selectedItem)
        {
            await Task.Delay(250);
            var newPage = new NewPage();
            newPage.BindingContext = selectedItem;
            await App.Current.MainPage.Navigation.PushAsync(newPage);
        }
    }
}

Output