Question

How can I suppress to close the form when hitting the OK button? I have the following code:

void __fastcall TfrmTillegg_velg::btnOkClick(TObject *Sender)
{
    if (exp1)
        ShowMessage("Not allowed"); // Don't close form
    else if (exp2)
        ShowMessage("Not allowed"); // Don't close form
    else
    {
        // Do something here
        Close();
    }
}

The project is written in Borland c++builder.

Answer 1

If you mean keeping the dialog created by ShowMessage open. then as far as I am aware, you cannot do this. The dialog displayed by ShowMessage will close whenever you click any of its buttons. If you want a popup dialog that will not close in this way, you will need to create a custom form yourself and control its behaviour according to your needs.

Just in case your question is referring to your main form closing, then you do have an explicit call to Close() within your button click event handler above that will cause your form to close whenever both of your exp1 and exp2 conditions are false.

 else     {         
        // Do something here         
        Close();     // THIS WILL CLOSE YOUR MAIN FORM.
 }