[Overview][Constants][Types][Classes][Procedures and functions][Index] | Reference for unit 'DBCtrls' (#lcl)

# TDBCheckBox.DoOnChange

Performs actions needed when the control is clicked.

## Declaration

Source position: dbctrls.pp line 676

`protected procedure TDBCheckBox.DoOnChange; override;`

## Description

DoOnChange is an overridden method in TDBCheckBox. It ensures that the internal TFieldDataLink is notified of a change to the control value.

If the OnDataChange event handler has been assigned for the field data link, its Edit, Modified, and UpdateRecord methods are called to store the new value for the control. If the linked dataset cannot be edited, the GetFieldCheckState method is called to get the checked state value stored to the State property.

The OnDataChange event handler in the data link is temporarily unassigned prior to updating the field value. The handler is reassigned when the actions have been completed.

DoOnChange calls the inherited method to signal the OnEditingDone and OnChange event handlers in ancestor classes.

## See also

TDBCheckBox.State |  | The check, unchecked, or grayed state for the control.
TDBCheckBox.GetFieldCheckState |  | GetFieldCheckState - returns the check box state for the current field.
TFieldDataLink.Edit |  | Edit - if the field can be modified, performs inherited Edit and shows editing status.
TFieldDataLink.Modified |  | Updates the class when the linked dataset enters an edit state.
TButtonControl.DoOnChange |  | Signals the OnEditingDone and OnChange event handlers (when assigned).
TDataLink.UpdateRecord