(Solved) Why is FScrollBars[isb].Value:=sNum; causing FMX to crash? (open source) VCL version doesn't crash!

[Al T 12]

procedure TFormAthenaVST.UpdateEditorParameter(index:integer;value: double);
VAR isb:integer;
    sNum:single;
begin
  WriteLog('TFormAthenaVST.UpdateEditorParameter(index:' + index.ToString + ' value:' + value.ToString);
  for isb:=0 to 2 do
    if index = ID_CUTOFF+isb then
      begin
        WriteLog('FScrollBars[' + isb.ToString + '].Value:=round(100*value)');
        sNum := round(100*value);
        WriteLog('sNum = ' + sNum.ToString);
        FScrollBars[isb].Value:=sNum;
        WriteLog('AFTER FScrollBars[isb].Value:=sNum;');
      end;
  WriteLog('TFormAthenaVST.UpdateEditorParameter END');
end;

https://github.com/War3Evo/RMSVST3/blob/Delphi-11.0/FMX_AthenaVST3/UAthenaVSTForm.pas#L149-L164

 

You can find all the source code here: https://github.com/War3Evo/RMSVST3/tree/Delphi-11.0/FMX_AthenaVST3

 

WriteLog uses CodeSite Express... CakeWalk by BandLabs crashes on FScrollBars[isb].Value:=sNum;

 

The VCL version does not crash but also uses FScrollBars[isb].Position:=round(100*value);

 

Your help is much appreciated!

 

Edited November 19, 2022 by Al T
CodeSite Express

[Al T 12]

I'm starting to guess I need to convert Int64 to Single... opps

 

Is there a directive I need to enable for Delphi to catch that before I compile it??

 

--okay that isn't what I thought it was... still stumped.

 

I'm now thinking

procedure TFormAthenaVST.UpdateEditorParameter(index:integer;value: double);

the value needs a rename??

 

Edited November 19, 2022 by Al T

[Al T 12]

okay.. it isn't the value or sNum...

 

It's FScrollBars[isb]

 

something about FScrollBars[isb] crashes it... cause I called:

 

procedure TFormAthenaVST.UpdateEditorParameter(index:integer; dvalue: double);
VAR isb:integer;
    sNum:single;
begin
  WriteLog('TFormAthenaVST.UpdateEditorParameter(index:' + index.ToString + ' dvalue:' + dvalue.ToString);
  for isb:=0 to 2 do
    if index = ID_CUTOFF+isb then
      begin
        WriteLog('FScrollBars[' + isb.ToString + '].Value:=(100*value)');
        //sNum := round(100*dvalue);
        sNum := 100*dvalue;
        WriteLog('FScrollBars[isb].BeginUpdate');
        FScrollBars[isb].BeginUpdate;
        WriteLog('sNum = ' + sNum.ToString);
        FScrollBars[isb].Value:=sNum;
        WriteLog('FScrollBars[isb].EndUpdate');
        FScrollBars[isb].EndUpdate;
        WriteLog('AFTER FScrollBars[isb].Value:=sNum;');
      end;
  WriteLog('TFormAthenaVST.UpdateEditorParameter END');
end;

It crashes right after WriteLog('FScrollBars[isb].BeginUpdate');

[Al T 12]

Solved:

 

procedure FormCreate(Sender: TObject);  IS in the source code... but on the form component it is not assigned to the procedure!