VB 总结类、对象、封装的含义

（1）创建学生Student类，它包含三个属性：整型属性学号（NO）、字符型属性姓名（Name）、日期型属性生日（BirthDay），一个输出的方法PrintInformation，其中，输出信息包含学号、姓名、生日。

（2）把1题中增加年龄（Age）属性，该属性只读，输出信息为：学号、姓名、年龄。

（3）把2题中定义一个构造函数，该构造函数可以包含（学号、姓名、生日）

Public Class Students
    Dim intNo As Integer
    Dim strName As String
    Dim datBirthday As Date

    Public Structure StudentsInfo
        Dim NO As Integer
        Dim Name As String
        Dim Birthday As Date
    End Structure

    Public Sub New()
        intNo = 0
        strName = ""
        datBirthday = Now
    End Sub

    Public Function PrintInformation() As StudentsInfo
        Dim stuInformation As StudentsInfo
        With stuInformation
            .NO = intNo
            .Name = strName
            .Birthday = datBirthday
        End With

        Return stuInformation
    End Function

    Public Property NO()
        Get
            Return intNo
        End Get
        Set(ByVal value)
            intNo = value
        End Set
    End Property

    Public Property Name()
        Get
            Return strName
        End Get
        Set(ByVal value)
            strName = value
        End Set
    End Property

    Public Property BirthDay()
        Get
            Return datBirthday
        End Get
        Set(ByVal value)
            datBirthday = value
        End Set
    End Property
End Class

Public Class StudentsAddAge
    Inherits Students
    Dim intAge As Integer

    Public Structure StudentsInfoAddAge
        Dim NO As Integer
        Dim Name As String
        Dim Age As Integer
    End Structure

    Public Sub New()
        intAge = 0
    End Sub

    Public Property Age()
        Get
            Return intAge
        End Get
        Set(ByVal value)
            intAge = value
        End Set
    End Property

    Public Overloads Function PrintInformation(ByVal isPrintAge As Boolean) As StudentsInfoAddAge
        Dim stuInformation As StudentsInfoAddAge
        With stuInformation
            .NO = MyBase.NO
            .Name = MyBase.Name
            .Age = intAge
        End With
        Return stuInformation
    End Function
End Class

Public Class StudentsSubNew
    Inherits StudentsAddAge
    Public Sub New(ByVal NO As Integer, ByVal Name As String, ByVal BirthDay As Date)
        MyBase.NO = NO
        MyBase.Name = Name
        MyBase.BirthDay = BirthDay
    End Sub
End Class