Tài liệu Classes pdf

[ Team LiB ]A.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 DataE

[ Team LiB ]

A.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 DataException : SystemException {

// Member definitions

}

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

Public Class DataException

Inherits SystemException

' 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 A-2

Table A-2 C# and equivalent VB class modifiers

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 DataSet : MarshalByValueComponent, IListSource,

ISupportInitialize, ISerializable

In VB, the 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 DataSet class in C# would

appear as follows in VB:

Public Class DataSet

Inherits MarshalByValueComponent

Implements IListSource, ISupportInitalize, ISerializable

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