TDBGrid reports "Invalid Property Value" for Datasource
lazarus / 16-Databases

----------------------------------------------------------------------
phil_v · 2012-12-11 22:14

Lazarus 1 2012-10-09
FPC 2.6.0 SVN 38415
i386-win32-win32/win64
ZEOS Lib 7.0
Firebird 2.5

Hi hope you can help.
I have a Datamodule (DM) with a Zconnection and a number of different
TZQuery/TDatasource components all using the same ZConnection.

On another form I have a TPagecontrol with 4 pages.
The form Uses the datamodule.
On the first page I have 4 TDBGrid components with datasource set to
each of 4 Tdatasources in the DM.
These 4 TDBgrids all work OK.
On another page of the TPageControl I have a TDBGrid, but I cannot set
its Datasource property from the IDE.
I get error "Invalid Property Value";

To work around this I set the Datasource property in the OnShow event
of the TTabsheet thus :-

procedure TSchedFrm.TabSheet4Show(Sender: TObject);
begin
 DM.VAQuery.Active:= True;                  // TZQuery in DM
 VAGrid.DataSource := DM.VASrc;          // TDBGrid on Tabsheet
 DBNavigator1.DataSource := DM.VASrc; // DBNavigator on Tabsheet
end;

Is it a Lazarus bug that I cannot set the Datasource property from the
IDE Please ?

----------------------------------------------------------------------
phil_v · 2013-01-14 22:35

POST Update :
I cannot set the Datasource property of any TDBGRID on the PageControl
Tabsheets.
The property is set programatically in the OnShow event of each
Tabsheet.

----------------------------------------------------------------------
phil_v · 2013-01-15 01:07

SOLVED.
I reconstructed a new form and copied all the objects from old to new
form, and the TDBGrid Datasource properties all displayed the
datasources from the Datamodule.

----------------------------------------------------------------------
teos · 2013-01-19 20:13

If the list of datasources is empty for your DBGrid and "invalid
property value" is raized when you enter the name yourself, that is
because the form/datamodule where the datasource is on, is not in the
uses of the form on which the DBGrid is: the unit cannot be scanned
and therefore the list is empty.

Use ALT+F11, add the unit and your issue is gone. In the situation you
describe, I can imagine that you wanna keep datasources on the
datamodule.