Question

I am just starting .Net development (C#) and have come across some code that has me slightly confused….

If I have

Form myForm = new Form();

What does the following line actually do:

Application.Run(myForm);

Does it essentially do the same thing as myForm.ShowDialog() or myForm.Show() (that’s what I thought, when running a form will do)…..

I always find that the msdn is a poor resource for properly explaining material to new comers

Answer 1

Application.Run(myForm); makes that form visible to user. It is the first form which get loaded in memory. And it runs this form in a message loop, so that you get all user events.

Short Answer:

Application.Run begins running a standard application message loop on the current thread.

Long Answer:

Application.Run causes the windows application enters the message loop within Winmain to process various windows messages the OS posts to a message queue.The message loop, “Loops” until its receives a WM_QUIT message. It uses GetMessage and PeekMessage to retrive messages and PostMessage to sent the retrived messages to Windows procedure.

If you do

Form myForm = new Form(); 
myForm.Show();

it will show the form and exit out. You will use new Form() & .Show() when you want to launch a new form from existing form.

Hope this answers your question.