Is it possible to hide components from delphi code

Jon

Is it possible to hide components (e.g. check the value of a data memo and hide if value is zero) using code in delphi. ?

gordk

yes but awkward easier to do it in the internal obp event of the memo or the band containing the memo.

Jon

gordk wrote: »

yes but awkward easier to do it in the internal obp event of the memo or the band containing the memo.

Yes I used the report events in FR2, but the FR4 version that comes with XE5 does not give access to events in the report.

It returns Null where ever I seem check the value of the data using
m = frxReport.FindObject('frxMemoName') As TfrxMemoView;
v = TfrxMemoView(m).DataSet.Value[TfrxMemoView(m).DataField];

And just returns the field (eg [frxdbDataset.'fieldname']) using
m = frxReport.FindObject('frxMemoName') As TfrxMemoView;
m.Text

Can you tell me how it is done in delphi code?

gordk

create a variable in the report connect it to the data field
you can get its value in delphi.
assuming the memo is on masterdata1
use the obp event of the report in delphi
if sender.name = 'Masterdata1'
then
if frxreport1.variables.value = whatever your testing for
then
m = frxReport.FindObject('frxMemoName') As TfrxMemoView;
m.visible :=false;

Jon

gordk wrote: »

create a variable in the report connect it to the data field
you can get its value in delphi.
assuming the memo is on masterdata1
use the obp event of the report in delphi
if sender.name = 'Masterdata1'
then
if frxreport1.variables.value = whatever your testing for
then
m = frxReport.FindObject('frxMemoName') As TfrxMemoView;
m.visible :=false;

Thank you for your help. When the OnBeforePrint code runs I get an 'Invalid variant operation' message at the line with if frxreport1.variables.value = 0 ?

To test I commented out obp code, added the variable into a memo on the data band and it shows the data so variable appears to be OK. So I then edited above line to use a system variable frxreport1.variables.value and got the same message.

I must be missing something subtle here, but I can't see what?

gpi

Try to use frxreport1.Variables.variables or frxReport1.Calc('<variablename>')

Jon

gpi wrote: »

Try to use frxreport1.Variables.variables or frxReport1.Calc('<variablename>')

Thanks for your help. I get the same problem though.

Jon

OK I have found the solution. This is such a basis requirement and not in any of the help documents, so here is the solution for anyone else who needs it.

As well as setting the datafield in the Text of the TfrxMemoView, the DataSet and DataField must also be set in the Properties of TfrxMemoView, or the values are not visible from the code.

Delphi OnBeforePrint Code:

If Sender.Name = 'MasterData1' then begin
m := frxReport1.FindObject('Memo1') As TfrxMemoView;
v := TfrxMemoView(m).DataSet.Value[TfrxmemoView(m).DataField];
if v = 0 then
m.Visible := false
else
m.Visible := true;
end

nixbeau

Please, how declare variable 'v'?

gpi

var v: Variant;