TreeListColumn.Validate Event
Enables you to validate the active editor’s value.
Namespace: DevExpress.Xpf.Grid
Assembly: DevExpress.Xpf.Grid.v19.2.dll
Declaration
Event Data
The Validate event's data class is TreeListCellValidationEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Cell | Gets the CellValue object consisting of information about the cell being processed. Inherited from GridCellValidationEventArgs. |
| CellValue | Gets the cell’s old valid value. Inherited from GridCellValidationEventArgs. |
| Column | Gets the column that contains the processed cell. Inherited from GridCellValidationEventArgs. |
| 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. 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. |
| UpdateSource | Gets the action that caused the validation. Inherited from ValidationEventArgs. |
| Value | Gets the editor’s value. Inherited from ValidationEventArgs. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| InvokeEventHandler(Delegate, Object) | 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 RoutedEventArgs. |
| OnSetSource(Object) | 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 RoutedEventArgs. |
| SetError(Object, ErrorType) | Displays an error within the editor. Inherited from ValidationEventArgs. |
| SetError(Object) | Displays an error within the editor. Inherited from ValidationEventArgs. |
Remarks
When an end-user modifies the focused cell’s value and tries to save the changes (by pressing the ENTER key or moving focus to another cell), the treelist validates a new value. First, this value is validated by the editor itself. Then, the column’s Validate event is raised, allowing you to manually validate the cell’s value. Note this event is not fired when changing cell values in code.
To learn more, see Cell Validation.