S1151 — "Select...Case" clauses should not have too many lines of code

Why is this an issue?

The Select...Case statement should be used only to clearly define some new branches in the control flow. As soon as a case clause contains too many statements this highly decreases the readability of the overall control flow statement. In such case, the content of the case clause should be extracted into a dedicated procedure.

Noncompliant code example

With the default threshold of 3:

Select Case number
    Case 1 To 5 ' Noncompliant: 4 statements in the case
        MethodCall1("")
        MethodCall2("")
        MethodCall3("")
        MethodCall4("")
    Case Else
        ' ...
End Select

Compliant solution

Select Case number
    Case 1 To 5
        DoSomething()
    Case Else
        ' ...
End Select
...
Sub DoSomething()
    MethodCall1("")
    MethodCall2("")
    MethodCall3("")
    MethodCall4("")
End Sub