Run time crash using tmodStringGrid = class(tStringGrid).

[iru]

Environment: Linux Mint 20, Laz 2.0.12, fpc 3.2.0.

I have a main form with two StringGrids. I wish to add a couple of functions to move data from IBQuery fields to the cells in the grids.

Program compiles clean and executes.

Created a modified StringGrid with

  tModStringGrid = class(tStringGrid)
     Function LoadQ(InQ : tIBQuery) : String;
     ...
     ...
  end;

On the main form changed the origional StringGrids types to tModStringGrid and tidied up a few things.

Compiled clean, no errors.

On executing the program it CRASHES in the .lpr on Application.CreateForm(TFormMain, FormMain);
The exception is EClassNotFound, class tStringGrid not found.

The 'assembler' display shows 'CLASSES$_$TREADER_$__$$_FINDCOMPONENTCLASS$ANSISTRING$$TCOMPONENTCLASS'.

If I insert a 'DummyStringGrid : tStringGrid' into the FormMain the program compiles and RUNS correctly, NO crash.
The DummyStringGrid is not accessed or used in any way.

So am I doing something really odd or do we have a bug???

Any ideas, brilliant insights appreciated, Ian.

[iru]

Thank you for the response. I will implement and check in the next couple of days. Rather busy at the moment.

Ian

[lucamar]

All you need to do is add the unit "Grids" (where TStringGrid is declared) to your (interface) uses clause.

Lazarus makes this happen automatically when you add a control to the form, which is why adding a dummy string grid works.