Class SfTreeView

A SfTreeView class provides a way to display the information in hierarchical structure.

Inheritance
System.Object
SfTreeView
Implements
System.IDisposable
Xamarin.Forms.IElementConfiguration<SfTreeView>
Namespace: Syncfusion.XForms.TreeView
Assembly: Syncfusion.SfTreeView.XForms.dll
Syntax
public class SfTreeView : View, IDisposable, IParentThemeElement, IThemeElement, IElementConfiguration<SfTreeView>

Constructors

SfTreeView()

Initializes a new instance of the SfTreeView class.

Declaration
public SfTreeView()

Fields

AutoExpandModeProperty

Identifies the AutoExpandMode bindable property.

Declaration
public static readonly BindableProperty AutoExpandModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

CheckBoxModeProperty

Identifies the CheckBoxMode bindable property.

Declaration
public static readonly BindableProperty CheckBoxModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

CheckedItemsProperty

Identifies the CheckedItems bindable property.

Declaration
public static readonly BindableProperty CheckedItemsProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ChildPropertyNameProperty

Identifies the ChildPropertyName bindable property.

Declaration
public static readonly BindableProperty ChildPropertyNameProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

CollapseCommandProperty

Identifies the CollapseCommand bindable property.

Declaration
public static readonly BindableProperty CollapseCommandProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

CurrentItemProperty

Identifies the CurrentItem dependency property.

Declaration
public static readonly BindableProperty CurrentItemProperty
Field Value
Type
Xamarin.Forms.BindableProperty

ExpandActionTargetProperty

Identifies the ExpandActionTarget bindable property.

Declaration
public static readonly BindableProperty ExpandActionTargetProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ExpandCommandProperty

Identifies the ExpandCommand bindable property.

Declaration
public static readonly BindableProperty ExpandCommandProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ExpanderPositionProperty

Identifies the ExpanderPosition dependency property.

Declaration
public static readonly BindableProperty ExpanderPositionProperty
Field Value
Type
Xamarin.Forms.BindableProperty

ExpanderTemplateProperty

Identifies the ExpanderTemplate bindable property.

Declaration
public static readonly BindableProperty ExpanderTemplateProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ExpanderWidthProperty

Identifies the ExpanderWidth bindable property.

Declaration
public static readonly BindableProperty ExpanderWidthProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

FocusBorderColorProperty

Identifies the FocusBorderColor dependency property.

Declaration
public static readonly BindableProperty FocusBorderColorProperty
Field Value
Type
Xamarin.Forms.BindableProperty

FocusBorderThicknessProperty

Identifies the FocusBorderThickness dependency property.

Declaration
public static readonly BindableProperty FocusBorderThicknessProperty
Field Value
Type
Xamarin.Forms.BindableProperty

FullRowSelectProperty

Identifies the FullRowSelect dependency property.

Declaration
public static readonly BindableProperty FullRowSelectProperty
Field Value
Type
Xamarin.Forms.BindableProperty

HierarchyPropertyDescriptorsProperty

Identifies the HierarchyPropertyDescriptors bindable property.

Declaration
public static readonly BindableProperty HierarchyPropertyDescriptorsProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

HoldCommandProperty

Identifies the HoldCommand bindable property.

Declaration
public static readonly BindableProperty HoldCommandProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

IndentationProperty

Identifies the Indentation bindable property.

Declaration
public static readonly BindableProperty IndentationProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

IsAnimationEnabledProperty

Identifies the IsAnimationEnabled dependency property.

Declaration
public static readonly BindableProperty IsAnimationEnabledProperty
Field Value
Type
Xamarin.Forms.BindableProperty

IsScrollBarVisibleProperty

Identifies the IsScrollBarVisible bindable property.

Declaration
public static readonly BindableProperty IsScrollBarVisibleProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ItemHeightProperty

Identifies the ItemHeight bindable property.

Declaration
public static readonly BindableProperty ItemHeightProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ItemsSourceProperty

Identifies the ItemsSource bindable property.

Declaration
public static readonly BindableProperty ItemsSourceProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

ItemTemplateContextTypeProperty

Identifies the ItemTemplateContextType dependency property.

Declaration
public static readonly BindableProperty ItemTemplateContextTypeProperty
Field Value
Type
Xamarin.Forms.BindableProperty

ItemTemplateProperty

Identifies the ItemTemplate bindable property.

Declaration
public static readonly BindableProperty ItemTemplateProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

LoadOnDemandCommandProperty

Identifies the LoadOnDemandCommand bindable property.

Declaration
public static readonly BindableProperty LoadOnDemandCommandProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

NodePopulationModeProperty

Identifies the NodePopulationMode bindable property.

Declaration
public static readonly BindableProperty NodePopulationModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty

NodeSizeModeProperty

Identifies the NodeSizeMode dependency property.

Declaration
public static readonly BindableProperty NodeSizeModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty

NodesProperty

Identifies the Nodes bindable property.

Declaration
public static readonly BindableProperty NodesProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

NotificationSubscriptionModeProperty

Identifies the NotificationSubscriptionMode dependency property.

Declaration
public static readonly BindableProperty NotificationSubscriptionModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty

SelectedItemProperty

Identifies the SelectedItem dependency property.

Declaration
public static readonly BindableProperty SelectedItemProperty
Field Value
Type
Xamarin.Forms.BindableProperty

SelectedItemsProperty

Identifies the SelectedItems dependency property.

Declaration
public static readonly BindableProperty SelectedItemsProperty
Field Value
Type
Xamarin.Forms.BindableProperty

SelectionBackgroundColorProperty

Identifies the SelectionBackgroundColor dependency property.

Declaration
public static readonly BindableProperty SelectionBackgroundColorProperty
Field Value
Type
Xamarin.Forms.BindableProperty

SelectionForegroundColorProperty

Identifies the SelectionForegroundColor dependency property.

Declaration
public static readonly BindableProperty SelectionForegroundColorProperty
Field Value
Type
Xamarin.Forms.BindableProperty

SelectionModeProperty

Identifies the SelectionMode dependency property.

Declaration
public static readonly BindableProperty SelectionModeProperty
Field Value
Type
Xamarin.Forms.BindableProperty

TapCommandProperty

Identifies the TapCommand bindable property.

Declaration
public static readonly BindableProperty TapCommandProperty
Field Value
Type
Xamarin.Forms.BindableProperty
Remarks

This bindable property is read-only.

Properties

AutoExpandMode

Gets or sets the value which indicates how the nodes to be expanded while loading.

Declaration
public AutoExpandMode AutoExpandMode { get; set; }
Property Value
Type Description
AutoExpandMode

The default value is None.

CheckBoxMode

Gets or sets the value which indicates whether the CheckBoxMode is Individual or Recursive or None.

Declaration
public CheckBoxMode CheckBoxMode { get; set; }
Property Value
Type
CheckBoxMode
Remarks

By default, it will be Nonei.e.,No update in any of the tree view node’s IsChecked property value.

See Also

CheckedItems

Gets or sets list checked items list. Maintains list of data objects based on IsChecked.

Declaration
public ObservableCollection<object> CheckedItems { get; set; }
Property Value
Type
System.Collections.ObjectModel.ObservableCollection<System.Object>
Remarks

This property maintains checked items only when you are binding ItemsSource to TreeView. To support recursive check programatically set CheckBoxMode as Recursive and NodePopulationMode as Instant. It does not support runtime changes in collection which is bind to CheckedItems.

See Also

ChildPropertyName

Gets or sets the property name for the child object where ItemsSource is used to define the items for this tree.

Declaration
public string ChildPropertyName { get; set; }
Property Value
Type
System.String

CollapseCommand

Gets or sets the System.Windows.Input.ICommand which will be executed when the TreeViewNode is being collapsed.

Declaration
public ICommand CollapseCommand { get; set; }
Property Value
Type
System.Windows.Input.ICommand
Examples
SfTreeView treeview = new SfTreeView();
treeview.CollapseCommand = viewModel.CollapsingCommand;

public class CommandViewModel
{
  private Command<Object> collapsingCommand;

  public Command<object> CollapsingCommand
  {
      get { return collapsingCommand; }
      set { collapsingCommand = value; }
  }

  public CommandViewModel()
  {
      CollapsingCommand = new Command<object>(CollapsingCommandMethod);
  }

  private void CollapsingCommandMethod(object obj)
  {


  }
}

CurrentItem

Gets or sets the current selected item.

Declaration
public object CurrentItem { get; set; }
Property Value
Type Description
System.Object

The current item.

ExpandActionTarget

Gets or sets a value indicating whether expanding and collapsing of nodes can be performed only by tapping in expander view or in both expander view and content view.

Declaration
public ExpandActionTarget ExpandActionTarget { get; set; }
Property Value
Type
ExpandActionTarget

ExpandCommand

Gets or sets the System.Windows.Input.ICommand which will be executed when the TreeViewNode is being expanded.

Declaration
public ICommand ExpandCommand { get; set; }
Property Value
Type
System.Windows.Input.ICommand
Examples
SfTreeView treeview = new SfTreeView();
treeview.ExpandCommand = viewModel.ExpandingCommand;

public class CommandViewModel
{
  private Command<Object> expandingCommand;

  public Command<object> ExpandingCommand
  {
      get { return expandingCommand; }
      set { expandingCommand = value; }
  }

  public CommandViewModel()
  {
      ExpandingCommand = new Command<object>(ExpandingCommandMethod);
  }

  private void ExpandingCommandMethod(object obj)
  {


  }
}

ExpanderPosition

Gets or sets the expander position in treeview. Default value is Start.

Declaration
public ExpanderPosition ExpanderPosition { get; set; }
Property Value
Type
ExpanderPosition

ExpanderTemplate

Gets or sets the data template for the Expander View of tree view item in SfTreeView.

Declaration
public DataTemplate ExpanderTemplate { get; set; }
Property Value
Type
Xamarin.Forms.DataTemplate

ExpanderWidth

Gets or sets the width of expander in tree view item.

Declaration
public double ExpanderWidth { get; set; }
Property Value
Type
System.Double

FocusBorderColor

Gets or sets the border color for the current focused item for UWP platform.

Declaration
public Color FocusBorderColor { get; set; }
Property Value
Type
Xamarin.Forms.Color
Remarks

For Android and iOS platform, the default color is Xamarin.Forms.Color.Transparent and for UWP platform, the default color is Color.FromHex("#D5D5D5").

FocusBorderThickness

Gets or sets the border thickness for the current focused item for UWP platform.

Declaration
public Thickness FocusBorderThickness { get; set; }
Property Value
Type
Xamarin.Forms.Thickness
Remarks

For Android and iOS platform, the default thickness is 0 and for UWP platform, the default thickness is 1.

FullRowSelect

Gets or sets a value indicating whether the selection spans the width of tree view control.

Declaration
public bool FullRowSelect { get; set; }
Property Value
Type
System.Boolean
Remarks

Default value false, where the selection start from indent level only.

HierarchyPropertyDescriptors

Gets or sets the list of HierarchyPropertyDescriptors which holds list of HierarchyPropertyDescriptor that provides information of type and property name. TreeView generates the child nodes based ChildPropertyName if the type of data object matches TargetType.

Declaration
public HierarchyPropertyDescriptors HierarchyPropertyDescriptors { get; set; }
Property Value
Type
HierarchyPropertyDescriptors

HoldCommand

Gets or sets the System.Windows.Input.ICommand which will be executed when hold on the TreeViewNode.

Declaration
public ICommand HoldCommand { get; set; }
Property Value
Type
System.Windows.Input.ICommand
Examples
SfTreeView treeview = new SfTreeView();
treeview.HoldCommand = viewModel.HoldingCommand;
public class CommandViewModel
{
  private Command<Object> holdingCommand;

  public Command<object> HoldingCommand
  {
      get { return holdingCommand; }
      set { holdingCommand = value; }
  }

  public CommandViewModel()
  {
      HoldingCommand = new Command<object>(HoldingCommandMethod);
  }

  private void HoldingCommandMethod(object obj)
  {


  }
}

Indentation

Gets or sets the distance to indent each child of tree view item in SfTreeView.

Declaration
public double Indentation { get; set; }
Property Value
Type
System.Double

IsAnimationEnabled

Gets or sets a value indicating whether the selection spans the width of tree view control.

Declaration
public bool IsAnimationEnabled { get; set; }
Property Value
Type
System.Boolean

IsScrollBarVisible

Gets or sets a value indicating whether to display the scrollbar or not.

Declaration
public bool IsScrollBarVisible { get; set; }
Property Value
Type
System.Boolean
Remarks

ScrollBar cannot be updated at runtime.

Examples
SfTreeView treeView = new SfTreeView();
treeView.IsScrollBarVisible = true;

ItemHeight

Gets or sets the height of each tree view item in SfTreeView.

Declaration
public double ItemHeight { get; set; }
Property Value
Type
System.Double

ItemsSource

Gets or sets the source items to the template and display in SfTreeView.

Declaration
public object ItemsSource { get; set; }
Property Value
Type
System.Object

ItemTemplate

Gets or sets the data template for the Content View of tree view item in SfTreeView.

Declaration
public DataTemplate ItemTemplate { get; set; }
Property Value
Type
Xamarin.Forms.DataTemplate

ItemTemplateContextType

Gets or sets the binding context type for treeview items. Note: It will be applicable for bound mode only. For Unbound mode, TreeViewNode will be the binding context for each treeview item.

Declaration
public ItemTemplateContextType ItemTemplateContextType { get; set; }
Property Value
Type
ItemTemplateContextType
Remarks

CheckBoxMode and CheckedItems are applicable for only in Node.

LoadOnDemandCommand

Gets or sets the System.Windows.Input.ICommand which will be executed when tap on the expander.

Declaration
public ICommand LoadOnDemandCommand { get; set; }
Property Value
Type
System.Windows.Input.ICommand
Remarks

It is applicable for bound mode only. Return true in CanExecute method of this command to enable expander icon and also to execute on demand loading for that node, else return false.

NodePopulationMode

Gets or sets the value that indicates whether the child nodes should be populated when treeview is loaded or when the node is expanded only.

Declaration
public TreeNodePopulationMode NodePopulationMode { get; set; }
Property Value
Type
TreeNodePopulationMode
Remarks

When NodePopulationMode is OnDemand, the child nodes will be populated when the parent nodes are expanded only. When NodePopulationMode is Instant, all the nodes will be populated when SfTreeView initially loaded. The default value is OnDemand. This property is applicable for Bound mode only.

Nodes

Gets or sets the collection of tree view nodes that are assigned to tree view control in Unbound mode..

Declaration
public TreeViewNodeCollection Nodes { get; set; }
Property Value
Type
TreeViewNodeCollection

NodeSizeMode

Gets or sets the node size mode value that indicates whether dynamic size changes should be enabled or disabled for tree view items.

Declaration
public NodeSizeMode NodeSizeMode { get; set; }
Property Value
Type
NodeSizeMode
Remarks

By default value, the NodeSizeMode is NodeSizeMode.None.

NotificationSubscriptionMode

Gets or sets the value that indicates whether to subscribe collection and property changes of data object to perform realtime data update. When binding ItemsSource, TreeView subscribes to collection and property changes of data object based on NotificationSubscriptionMode.

Declaration
public NotificationSubscriptionMode NotificationSubscriptionMode { get; set; }
Property Value
Type
NotificationSubscriptionMode
Remarks

When NotificationSubscriptionMode is CollectionChange, TreeView updated its tree structure when child items collection gets changed. When NotificationSubscriptionMode is Property change, TreeView updates its ChildItems when associated collection property gets changed. The default value is None.

Examples
SfTreeView treeView = new SfTreeView();
treeView.NotificationSubscriptionMode = NotificationSubscriptionMode.CollectionChange | NotificationSubscriptionMode.PropertyChange;

SelectedItem

Gets or sets the first selected item.

Declaration
public object SelectedItem { get; set; }
Property Value
Type Description
System.Object

The selected item.

SelectedItems

Gets or sets the selected items for selection.

Declaration
public ObservableCollection<object> SelectedItems { get; set; }
Property Value
Type
System.Collections.ObjectModel.ObservableCollection<System.Object>

SelectionBackgroundColor

Gets or sets the selection background color for the selected item.

Declaration
public Color SelectionBackgroundColor { get; set; }
Property Value
Type
Xamarin.Forms.Color
Remarks

The default color is Color.FromHex("#F4F4F4").

SelectionForegroundColor

Gets or sets the selected item foreground color. Note: It will applicable for unbound mode only.

Declaration
public Color SelectionForegroundColor { get; set; }
Property Value
Type
Xamarin.Forms.Color
Remarks

The default color is Color.FromHex("#007CEE").

SelectionMode

Gets or sets the selection mode for selection.

Declaration
public SelectionMode SelectionMode { get; set; }
Property Value
Type
SelectionMode
Remarks

By default value, the SelectionMode is SelectionMode.Single.

TapCommand

Gets or sets the System.Windows.Input.ICommand which will be executed when tap on the TreeViewNode.

Declaration
public ICommand TapCommand { get; set; }
Property Value
Type
System.Windows.Input.ICommand
Examples
SfTreeView treeview = new SfTreeView();
treeview.TapCommand = viewModel.TappedCommand;

public class CommandViewModel
{
  private Command<Object> tappedCommand;

  public Command<object> TappedCommand
  {
      get { return tappedCommand; }
      set { tappedCommand = value; }
  }

  public CommandViewModel()
  {
      TappedCommand = new Command<object>(TappedCommandMethod);
  }

  private void TappedCommandMethod(object obj)
  {


  }
}

Methods

BringIntoView(TreeViewNode, Boolean, Boolean, ScrollToPosition)

Attempts to bring the tree view item into view by scrolling.

Declaration
public void BringIntoView(TreeViewNode item, bool disableAnimation = false, bool canExpand = false, ScrollToPosition scrollToPosition)
Parameters
Type Name Description
TreeViewNode item

Represents the TreeViewNode to scroll.
System.Boolean disableAnimation

true to disable scroll animation while changing the view; otherwise, false. The default is false.
System.Boolean canExpand

true to expand the collapsed nodes and bring the collapsed node into view; otherwise, false. The default is false.
ScrollToPosition scrollToPosition

Defines position in the view to which node is scrolled.
Remarks

Need to set NodePopulationMode property to Instant for populating all the nodes to bring the collapsed node into view while calling this method with 'canExpand' parameter as true.

BringIntoView(Object, Boolean, Boolean, ScrollToPosition)

Attempts to bring the tree view item into view by scrolling.

Declaration
public void BringIntoView(object dataObject, bool disableAnimation = false, bool canExpand = false, ScrollToPosition scrollToPosition)
Parameters
Type Name Description
System.Object dataObject

Represents the data object associated with TreeViewNode to scroll.
System.Boolean disableAnimation

true to disable scroll animation while changing the view; otherwise, false. The default is false.
System.Boolean canExpand

true to expand the collapsed nodes and bring the collapsed node into view; otherwise, false. The default is false.
ScrollToPosition scrollToPosition

Defines position in the view to which object is scrolled.
Remarks

Need to set NodePopulationMode property to Instant for populating all the nodes to bring the collapsed node into view while calling this method with 'canExpand' parameter as true.

CollapseAll()

Collapses all the nodes in the SfTreeView.

Declaration
public void CollapseAll()

CollapseNode(TreeViewNode)

Collapses the specified TreeViewNode.

Declaration
public void CollapseNode(TreeViewNode item)
Parameters
Type Name Description
TreeViewNode item

Specifies the TreeViewNode to collapse it from the view.

CollapseNodes(Int32)

Collapses all the tree view items based on the specified level.

Declaration
public void CollapseNodes(int level = -1)
Parameters
Type Name Description
System.Int32 level

Specifies the level of TreeViewNode to collapse all the TreeViewItem from the view.

Dispose()

Dispose all the allocated resources.

Declaration
public void Dispose()

Dispose(Boolean)

Dispose the instances, if parameter is true.

Declaration
protected virtual void Dispose(bool disposing)
Parameters
Type Name Description
System.Boolean disposing

Represents the boolean value for disposing objects.

ExpandAll()

Expands all the nodes in the SfTreeView.

Declaration
public void ExpandAll()

ExpandNode(TreeViewNode)

Expands the specified TreeViewNode.

Declaration
public void ExpandNode(TreeViewNode item)
Parameters
Type Name Description
TreeViewNode item

Specifies the TreeViewNode to expand it in the view.

ExpandNodes(Int32)

Expands all the tree view items based on the specified level.

Declaration
public void ExpandNodes(int level = -1)
Parameters
Type Name Description
System.Int32 level

Specifies the level of TreeViewNode to expand all the TreeViewItems in the view.

GetCheckedNodes()

Get the all checked nodes in the SfTreeView. When binding ItemsSource, you can get the checked items list using CheckedItems.

Declaration
public ObservableCollection<TreeViewNode> GetCheckedNodes()
Returns
Type Description
System.Collections.ObjectModel.ObservableCollection<TreeViewNode>

Returns the collection of checked nodes.
See Also

On<T>()

Method to get platform specific properties.

Declaration
public IPlatformElementConfiguration<T, SfTreeView> On<T>()
    where T : IConfigPlatform
Returns
Type Description
Xamarin.Forms.IPlatformElementConfiguration<T, SfTreeView>

Return platform specific properties.
Type Parameters
Name Description
T

Represents the platform type.

OnMeasure(Double, Double)

This method is called during the measure pass of a layout cycle to get the desired size of an element.

Declaration
protected override SizeRequest OnMeasure(double widthConstraint, double heightConstraint)
Parameters
Type Name Description
System.Double widthConstraint

The available width for the element to use.
System.Double heightConstraint

The available height for the element to use.
Returns
Type Description
Xamarin.Forms.SizeRequest

A Xamarin.Forms.SizeRequest which contains the desired size of the element.
Remarks

The results of this method will be (-1, -1) if the element has not yet been realized with a platform specific backing control. Overriding this method does not require a call to the base class so long as a valid SizeRequest is returned.

RefreshView(Boolean)

Refresh the treeviewitem in UI.

Declaration
public void RefreshView(bool canResetNodeView = false)
Parameters
Type Name Description
System.Boolean canResetNodeView

Indicates to reset tree node views.

ResetTreeViewItems(Object)

Method to reset the visible treeview item’s. If parameter is null, visible treeview items will reset else, particular treeview item will reset.

Declaration
public void ResetTreeViewItems(object dataObject = null)
Parameters
Type Name Description
System.Object dataObject

For Unbound mode, data represents the TreeViewNode and for Bound mode, it represents the data object associated with TreeViewNode.

Events

ItemDoubleTapped

Occurs when the TreeViewItem's ContentView is double tapped.

Declaration
public event EventHandler<ItemDoubleTappedEventArgs> ItemDoubleTapped
Event Type
Type
System.EventHandler<ItemDoubleTappedEventArgs>

ItemHolding

Occurs when the TreeViewItem's ContentView is long pressed.

Declaration
public event EventHandler<ItemHoldingEventArgs> ItemHolding
Event Type
Type
System.EventHandler<ItemHoldingEventArgs>
Remarks

We can use the platform specific property Syncfusion.XForms.TreeView.PlatformConfiguration.WindowsSpecific.TreeView.HoldGesture(Xamarin.Forms.IPlatformElementConfiguration{Xamarin.Forms.PlatformConfiguration.Windows,Syncfusion.XForms.TreeView.SfTreeView}) for UWP platfom, to choose the intractions that supports for Holding an item. When Syncfusion.XForms.TreeView.PlatformConfiguration.WindowsSpecific.TreeView.HoldGesture(Xamarin.Forms.IPlatformElementConfiguration{Xamarin.Forms.PlatformConfiguration.Windows,Syncfusion.XForms.TreeView.SfTreeView}) is Hold, the holding event triggered only when hold by touch. When Syncfusion.XForms.TreeView.PlatformConfiguration.WindowsSpecific.TreeView.HoldGesture(Xamarin.Forms.IPlatformElementConfiguration{Xamarin.Forms.PlatformConfiguration.Windows,Syncfusion.XForms.TreeView.SfTreeView}) is HoldWithMouse, the holding event triggered only when hold using mouse pointer. The default value is Hold. This enumeration has a System.FlagsAttribute attribute that allows a bitwise combination of its member values. This is applicable only for UWP.

Examples
SfTreeView treeView = new SfTreeView();
treeView.On<Windows>().SetHoldGesture(HoldGestureSettings.HoldWithMouse | HoldGestureSettings.Hold);

ItemTapped

Occurs when the TreeViewItem's ContentView is tapped.

Declaration
public event EventHandler<ItemTappedEventArgs> ItemTapped
Event Type
Type
System.EventHandler<ItemTappedEventArgs>

Loaded

Occurs when the SfTreeView is loaded for the first time.

Declaration
public event EventHandler<TreeViewLoadedEventArgs> Loaded
Event Type
Type
System.EventHandler<TreeViewLoadedEventArgs>

NodeChecked

Occurs when an IsChecked is being changed.

Declaration
public event EventHandler<NodeCheckedEventArgs> NodeChecked
Event Type
Type
System.EventHandler<NodeCheckedEventArgs>

NodeCollapsed

Occurs when an TreeViewNode is collapsed.

Declaration
public event EventHandler<NodeExpandedCollapsedEventArgs> NodeCollapsed
Event Type
Type
System.EventHandler<NodeExpandedCollapsedEventArgs>

NodeCollapsing

Occurs when an TreeViewNode is being collapsed.

Declaration
public event EventHandler<NodeExpandingCollapsingEventArgs> NodeCollapsing
Event Type
Type
System.EventHandler<NodeExpandingCollapsingEventArgs>

NodeExpanded

Occurs when an TreeViewNode is expanded.

Declaration
public event EventHandler<NodeExpandedCollapsedEventArgs> NodeExpanded
Event Type
Type
System.EventHandler<NodeExpandedCollapsedEventArgs>

NodeExpanding

Occurs when an TreeViewNode is being expanded.

Declaration
public event EventHandler<NodeExpandingCollapsingEventArgs> NodeExpanding
Event Type
Type
System.EventHandler<NodeExpandingCollapsingEventArgs>

QueryNodeSize

Occurs whenever an item comes into view and query the item size.

Declaration
public event EventHandler<QueryNodeSizeEventArgs> QueryNodeSize
Event Type
Type
System.EventHandler<QueryNodeSizeEventArgs>
Remarks

SfTreeView supports auto height feature,by using this event. We can define whether the specified size can be set to the item or not by handling the QueryNodeSize event.

Examples
SfTreeView treeview = new SfTreeView();
treeview += TreeView_QueryNodeSize;

void TreeView_QueryNodeSize (object sender, QueryNodeSizeEventArgs e)
{
 e.Height = e.GetActualNodeHeight();
 e.Handled = true;
}

SelectionChanged

Occurs once the selection process has been completed for the selected item in the SfTreeView.

Declaration
public event EventHandler<ItemSelectionChangedEventArgs> SelectionChanged
Event Type
Type
System.EventHandler<ItemSelectionChangedEventArgs>

SelectionChanging

Occurs while selecting an item's contentview at the execution time.

Declaration
public event EventHandler<ItemSelectionChangingEventArgs> SelectionChanging
Event Type
Type
System.EventHandler<ItemSelectionChangingEventArgs>
Remarks

The SelectionChanging event is a cancelable event and can be canceled by handling the event and setting the Cancel property to true. However, if the event is canceled, the selection process for the selected TreeViewItem's contentview gets cancelled.

Implements

System.IDisposable
Xamarin.Forms.IElementConfiguration<>