TCustomForm.ActiveControl

Specifies the active control on the form.

Declaration

Source position: forms.pp line 770

Description

ActiveControl is a TWinControl property which contains the control which has focus on the form. The property value can be Nil if the form is hidden, disabled, or has never been activated.

Setting a new value for the property causes validity checks to be performed to ensure that the specified control can receive focus when the form is Visible. An EInvalidOperation exception is raised when the new property value contains:

• The current form instance.
• A control not parented by the current form instance.
• A control that returns False from its CanFocus method.

The SetWindowFocus method is called if the form is Active, and the ActiveChanged method is called.

The value in ActiveControl is updated in the FocusControl and DefocusControl methods.