对象（Object）和类（Class）的关系？

1. 对象属于某一类，即对象是某一个类的实例。例如：

Public Class Flight

    Private _name As String

 

    Public Property Name As String

        Get

 

            Return _name

        End Get

        Set(value As String)

            _name = value

        End Set

    End Property

 

    Public Sub New()

 

    End Sub

 

    Public Sub New(ByVal name As String)

        _name = name

    End Sub

 

End Class

 

Sub Main()

 

        Dim f1 = New Flight("MH370")

 

 

在上面的示例代码中Flight是类，表示“航班”；而f1是对象，用来表示具体的某一个航班，名叫“MH370”

2. 类是具有相同属性和行为的某一类对象的定义/描述

例如：我们可以将汽车、列车、飞机、轮船等这些具有运输能力，包含发动机的一系列对象定义一个类，名叫：Vehicle

 

Public Class Vehicle

    Private _speed As Double

 

    Public Property Speed As Double

        Get

 

        End Get

        Set(value As Double)

 

        End Set

    End Property

 

    '剩余燃料

    Public Property ResidualFuel As Double

        Get

 

        End Get

        Set(value As Double)

 

        End Set

    End Property

 

    '启动

    Public Overridable Sub Start()

 

        Call EngineStart()

 

    End Sub

 

    '紧急停止

    Public Sub StopImmediate()

 

    End Sub

 

    '引擎启动

    Public Sub EngineStart()

        Console.WriteLine("引擎启动...")

 

    End Sub

 

    Public Sub Whistle()

 

    End Sub

 

    '加/减速

    ''' <param name="increment">增量</param>

    Public Sub Accelerate(ByVal increment As Double)

 

    End Sub

 

End Class