TreeListView.ValidateNode Event

Enables you to specify whether the focused node's data is valid, and whether the node can lose focus.

Namespace: DevExpress.Xpf.Grid

Assembly: DevExpress.Xpf.Grid.v14.2.dll

Declaration

C#

public event TreeListNodeValidationEventHandler ValidateNode

VB.NET

Public Event ValidateNode As TreeListNodeValidationEventHandler

Event Data

The ValidateNode event's handler receives an argument of the TreeListNodeValidationEventArgs type. The following properties provide information specific to this event:

Property	Description
Culture	Gets the culture related to the validation. Inherited from ValidationEventArgs.
ErrorContent	Gets or sets an object that describes the validation error. Inherited from ValidationEventArgs.
ErrorType	Gets or sets the error type. Inherited from ValidationEventArgs.
Handled	Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
IsValid	Gets or sets a value specifying whether the value is valid. Inherited from ValidationEventArgs.
Node	Gets the processed node.
OriginalSource	Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent	Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Row	Gets the processed row.
Source	Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.
UpdateSource	Gets an object that invoked the BaseEdit.Validate event. Inherited from ValidationEventArgs.
Value	Gets the editor's new value. Inherited from ValidationEventArgs.

Remarks

Node validation is performed within the ValidateNode event handler. This event is automatically fired when a node is about to lose focus. To manually force node validation, call the DataViewBase.CommitEditing method.

The processed node is returned by the event parameter's TreeListNodeValidationEventArgs.Node property. After cell values have been obtained, you can verify whether these values meet your validity criteria. If the node fails validation, set the event's ValidationEventArgs.IsValid parameter to false. Otherwise, leave this parameter set to true.

To learn more, see Validating Rows.