DBGrid focus bug on MDI

Question

I got a DbGrid focus bug when I have it inside a MDIChildForm.

To reprocedure the bug:

• Create a MDI application
• At the main form, put a Panel and a Edit inside it
• Create a MDI Child form
• Put a DBGrid and assign data (with more than 1 record)

Now, run the application, and follow the steps:

• Click on the Grid, to focus at the first row
• Click on the Edit, to focus it
• Now try to click at another row of the dbgrid.

Bug:

• The dbgrid doesn't receives the focus, nothing happends!

I'm using Delphi 7.

Can someone help me with an workaround?

Answer 1

The problem is created by the Form.ActiveControl.

In this case, the MDI child is retaining the DBGrid as the active control after the Edit focused, and because of this the Windows.SetFocus isn't called after the dbgrid is clicked.

I solve the problem by overriding the TDBGrid.SetFocus:

type
    TMyDBGrid = class(TDBGrid)
    public
       procedure SetFocus; override;
    end;

procedure TMyDBGrid.SetFocus;
var
  form: TCustomForm;
begin
  inherited;

  // BUG-FIX: force the SetFocus if the current Control is Self but not focused!
  form := GetParentForm(Self);
  if (form <> nil) and (form.ActiveControl = Self) and not Focused then
    Windows.SetFocus(Self.Handle);
end;

Answer 2

I solved the problem by putting the line

self.setfocus2

in the event OnShow. I also added this same code to the OnActivate event. It works perfectly now.