Enables you to specify whether the focused node's data is valid, and whether the node can lose focus.
public event TreeListNodeValidationEventHandler ValidateNode
Public Event ValidateNode As TreeListNodeValidationEventHandler
The ValidateNode event's data class is TreeListNodeValidationEventArgs. The following properties provide information specific to this event:
|CancellationToken||Gets an object that notifies that the Update operation should be canceled. Inherited from GridRowValidationEventArgs.|
|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 icon 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. Inherited from GridRowValidationEventArgs.|
|RowHandle||Gets the processed row's handle. Inherited from GridRowValidationEventArgs.|
|Source||Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.|
|UpdateRowResult||Gets or sets a task that allows you to asynchronously post changes to an underlying data source (database). Inherited from GridRowValidationEventArgs.|
|UpdateSource||Gets the action that caused the validation. Inherited from ValidationEventArgs.|
|UseCancellationToken||Gets or sets whether the Update operation can be canceled. Inherited from GridRowValidationEventArgs.|
|Value||Gets the editor's value. Inherited from ValidationEventArgs.|
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 Row Validation.