Showing a modal form at program startup

[pedand]

What is the recommended way to show a modal form when a program starts? ShowModal->TForm2 can not be used in the constructor or in FormCreate for TForm1 but I guess this can be done in the project.cpp file (in WinMain just as for splash windows). Surely there must be a better way to collect user data for things like validating the user's permissions for an application etc.
Regards
Anders

[2ffat]

I've used two different ways to show forms at startup. The first comes from Borland C++ Builder How-To: The Definitive C++ Builder Problem-Solver by John Miano, Tom Cabanski, and Harold Howe. They show some code for making a form, in this case a splash screen, at startup. They put their code in the Form1.cpp. This is the C++ source created by Builder automatically. You usually don't edit this code but they recommend doing something like:

Code: Select all

WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
    try
    {
         Application->Initialize();
         Form2 = new TForm2(Application); // You add this
         Form2->Show(); // You add this
         Form2->Update(); // You add this
         Application->CreateForm(__classid(TForm1), &Form1);
         Application->Run();
    }
    catch (Exception &exception)
    {
         Application->ShowException(&exception);
    }
    return 0;
}

I prefer to do the following in my form's initialzation function. This is the first function in the C++ source code that you usually edit.

Code: Select all

__fastcall MyForm::TMyForm(TComponent* Owner)
    : TForm(Owner)
{
   
    // The following section of code is what you add
    TForm2 *My2Form = new TForm2(Application);
    try
    {
        My2Form->Show();
    }
    __finally
    {
        delete My2Form;
    }
    // The above section of code is what you add

}
//---------------------------------------------------------------------------


I prefer the second mainly because the __finally code will delete the form whether there is a problem or not thus freeing memory. I suppose you do the same in the previous example.

This is probably as clear as mud but it works for me.

[Guest]

Hi James,

I've used the technique in your first example before and it works fine but I don't like it. It seems, at least om my pc, that you should not update the Project|Options|Forms tab if you update the project.cpp file this way since the code behind the tab can change (=overwrite) the file contents. I once lost some work this way.

Your second example is much safer, more logical and clear as a mountain stream. Again thanks.
Anders