S2347 — Event handlers should comply with a naming convention

Why is this an issue?

Shared coding conventions allow teams to collaborate efficiently. This rule checks that all even handler names match a provided regular expression.

The default configuration is:

• Either in Pascal case, i.e. starting with an upper case letter, e.g. OnMyButtonClicked
• Or, a subject, in Pascal or camel case, followed by an underscore followed by an event name, in Pascal case, e.g. btn1_Clicked

Event handlers with a handles clause and two-parameter methods with EventArgs second parameter are covered by this rule.

Noncompliant code example

With the default regular expression ^(([a-z][a-z0-9]*)?([A-Z]{1,3}[a-z0-9]+)*([A-Z]{2})?_)?([A-Z]{1,3}[a-z0-9]+)*([A-Z]{2})?$:

Module Module1
    Sub subject__SomeEvent() Handles X.SomeEvent   ' Noncompliant - two underscores
    End Sub
End Module

Compliant solution

Module Module1
    Sub subject_SomeEvent() Handles X.SomeEvent    ' Compliant
    End Sub
End Module