ASP.NET.in.a.Nutshell.Second.Edition [Electronic resources]

G. andrew Duthie; matthew Macdonald

نسخه متنی -صفحه : 873/ 130
نمايش فراداده

22.2 Classes

C# uses the class statement along with opening and closing braces to indicate the beginning and end of a class definition. For example:

public class Form : ContainerControl {
// member definitions
}

In VB, a class definition is indicated by the Class... End Class construct:

Public Class Form 
' member definitions
End Class

In addition, C# classes can be marked as abstract or sealed; these correspond to the VB MustInherit and NonInheritable keywords, as shown in Table 22-2.

Table 22-2. C# and equivalent VB class modifiers

C# keyword

VB keyword

abstract

MustInherit

sealed

NonInheritable

C# uses the colon to indicate either inheritance or interface implementation. Both the base class and the implemented interfaces are part of the class statement. For example:

public class Control : Component, ISynchronizeInvoke, IWin32Window

In VB, a base class and any implemented interfaces are specified on separate lines immediately following the Class statement. A class's base class is indicated by preceding its name with the Inherits keyword; any implemented interfaces are indicated by the Implements keyword. Hence, the previous definition of the Control class in C# would appear as follows in VB:

Public Class Control
Inherits Component
Implements ISynchronizeInvoke, IWin32Window