dot and underscore characters

[positrom2]

Hello,
When looking for help on how to use EditText the following questions came up to me:
I understand that dot is used for working down on the properties of an object
like

EditText1.Text.Trim.Length = 0

But then I see that EditText1 is followed by an underscore character

Sub EditText_FocusChanged (HasFocus As Boolean)

(examples from EditText - Basic4android Wiki). So, should the second quote read EditText1_.... instead of EditText?

A question is also: Is there restriction to use dot and underscore characters in naming objects?

Thanks for answer.
positrom2

 

[Erel]

Dot is a special operator.
Underscore can be used in identifiers names, but not as the first character.

There is a convention that the event sub name should be EventName_Event.

 

[positrom2]

Thanks,
now I see some reason for my very flat learning curve. The underscore is present everywhere in the codes, but I did not know about the convention, so I never really understood. I never became friend of VB6 and successors (seems to be related to that).
regards, positrom2