TDBLookup.EmptyValue property
Value stored for the lookup control when a lookup value is not available.
Declaration
property EmptyValue: string read FEmptyValue write FEmptyVAlue;Description
EmptyValue is a
String property which contains the
value stored in the list of key values when no records are available in the
linked lookup dataset, or when the
NullValueKey shortcut is
pressed.
Use EmptyValue to specify a KeyField value automatically added to
the ControlItems property when the linked lookup dataset contains
no records. No entry is added to Controlitems when the value in EmptyValue is
an empty string (''). The value in DisplayEmpty is used for the
ListFielddisplayed in the control.
Use DisplayEmpty to specify the value displayed in the lookup
control when no records are available in the linked lookup dataset, or when
the NullValueKey shortcut is pressed.
The EmptyValue and DisplayEmpty properties were added in revision 62844, and released in LCL version 2.0.8 and higher.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.