TreeListView.ValidateNode Event
Allows you to validate node values.
Namespace: DevExpress.Xpf.Grid
Assembly: DevExpress.Xpf.Grid.v24.2.dll
NuGet Package: DevExpress.Wpf.Grid.Core
#Declaration
public event TreeListNodeValidationEventHandler ValidateNode
#Event Data
The ValidateNode event's data class is TreeListNodeValidationEventArgs. The following properties provide information specific to this event:
Property | Description |
---|---|
Cancellation |
Gets an object that notifies that the Update operation should be canceled.
Inherited from Grid |
Culture |
Gets the culture related to the validation.
Inherited from Validation |
Error |
Gets or sets an object that describes the validation error.
Inherited from Validation |
Error |
Gets or sets the error icon type.
Inherited from Validation |
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 Routed |
Is |
Inherited from Grid |
Is |
Gets or sets a value specifying whether the value is valid.
Inherited from Validation |
Node | Gets the processed node. |
Original |
Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class.
Inherited from Routed |
Routed |
Gets or sets the Routed |
Row |
Gets the processed row.
Inherited from Grid |
Row |
Gets the processed row’s handle.
Inherited from Grid |
Source |
Gets or sets a reference to the object that raised the event.
Inherited from Routed |
Update |
Gets or sets a task that allows you to asynchronously post changes to an underlying data source (database).
Inherited from Grid |
Update |
Gets the action that caused the validation.
Inherited from Validation |
Use |
Gets or sets whether the Update operation can be canceled.
Inherited from Grid |
Value |
Gets the editor’s value.
Inherited from Validation |
The event data class exposes the following methods:
Method | Description |
---|---|
Invoke |
When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation.
Inherited from Routed |
On |
When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes.
Inherited from Routed |
Set |
Marks the processed input value as invalid and displays an error within the editor with the specified error icon type.
Inherited from Validation |
Set |
Marks the processed input value as invalid and displays an error within the editor.
Inherited from Validation |
#Remarks
The GridControl raises the ValidateNode
event when the control saves changes to a data source. The save changes process starts when a user focuses another node, or you call the DataViewBase.CommitEditing method.
The Node property returns the processed node.
You can obtain cell values and verify if they meet your validation criteria. If these values are incorrect, set the IsValid property to false
.
Refer to the following topic for more information: Row Validation.
If you want to maintain a clean MVVM pattern and process the node validate operation in a View Model, create a command and bind it to the ValidateNodeCommand property.
Use the UpdateRowResult property to validate rows data asynchronously.