Differences between Application.MessageBox, Windows.MessageBox and Dialogs.MessageDlg in Delphi

Question

In Delphi; what are the differences between Application.MessageBox, Windows.MessageBox or Dialogs.MessageDlg? Or which is more efficient to use computer memory?

Answer 1

Windows.MessageBox is the WinAPI MessageBox, Application.MessageBox is a wrapper around it. Dialogs.MessageDlg however is a VCL form. So if you are concerned about memory or thread safety, the first two might be better suited. MessageDlg OTOH is more flexible and easier to use (IMHO, of course).

Nowadays, I'd consider task dialogs (TaskDialogIndirect, TTaskDialog or another wrapper).