delphi xe10.4 DBGrid DrawColumnCell

[sw4all 0]

Hello to everybody.
I need to add a button to each cell and use one click function.
Unfortunately I get an error Access violation at address ...

Thank you all.

Daniel

public
    { Public declarations }
    procedure btnChangeSClick(Sender: TObject);
   ...
   ...
   
procedure TfrmMain.btnChangeSkupinaClick(Sender: TObject);
begin
  frmSelectS.gridName := 'TEST';
  frmSelectS.ShowModal;
end;

procedure TfrmMain.grid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
  Field: TField;
  fixRect : TRect;
  btnChangeS: TButton;
begin

  Field := Column.Field;

  if (Column.Index = 0) then
  begin
    try
      btnChangeS.Create(grid1);
      btnChangeS.Parent := grid1;
      btnChangeS.Visible := True;
      btnChangeS.Caption := '...';
      btnChangeS.Width := 25;
      btnChangeS.Height := (Rect.Bottom - Rect.Top) - 2;
      btnChangeS.Left := (Rect.Left + Rect.Width) - (btnChangeS.Width +1);
      btnChangeS.Top := Rect.Top + 1;
      btnChangeS.OnClick := btnChangeSClick;
      grid1.DefaultDrawColumnCell(Rect, DataCol, Column, State);
    except
      On E: exception do
      begin
        ShowMessage(E.Message);
      end;
    end;
  end;

end;

 

Edited August 15, 2021 by sw4all

[Pat Foley 52]

Quote

btnChangeS.Create(grid1);

 

btnChangeS := TButton.Create(grid1);

[sw4all 0]

2 minutes ago, Pat Foley said:

btnChangeS := TButton.Create(grid1);

Yes.
Thank you so much for your quick help.
Everything is working.

[sw4all 0]

I see one more error and that is that the procedure still creates more and more buttons.

Please look in the upper left corner.

Sample video.

 

Edited August 15, 2021 by sw4all

[Lajos Juhász 295]

46 minutes ago, sw4all said:

I see one more error and that is that the procedure still creates more and more buttons.

It's not an error, it's how you've coded to create a new button in every paint event. Instead of that I would use the inbuild feature of the dbgrid.

 

On you column set ButtonStyle to cbsEllipsis then you can place your in the OnEditButtonClick event of the grid.

 

[sw4all 0]

26 minutes ago, Lajos Juhász said:

It's not an error, it's how you've coded to create a new button in every paint event. Instead of that I would use the inbuild feature of the dbgrid.

 

On you column set ButtonStyle to cbsEllipsis then you can place your in the OnEditButtonClick event of the grid.

 

Yes thank you.
The problem is that dgEditing will not be enabled, so the button will not appear.

Oh, just set DBGrid readOnly: = True;

Edited August 15, 2021 by sw4all

[sw4all 0]

Is there any way for the button to still be visible, not only when a cell is selected?

So that the user can see which cells he can edit.

Edited August 15, 2021 by sw4all