.net - VB.NET 中的引用资料

Question

我有点不清楚的是 VB.NET 中类的引用(指针？)。我要问的问题可以通过一些测试来回答，但我想知道是否有人可以发布一个像样的解释(或链接)。

如果您创建一个类:

Public Class ReferenceClass

    Private myBooleanValue As Boolean = False
    Public Property BooleanValue As Boolean
        Get
            Return myBooleanValue
        End Get
        Set(value As Boolean)
            myBooleanValue = value
        End Set
    End Property

End Class

然后是一个实际使用该类作为属性的类:

Public Class UsingClass

     Private myReference As ReferenceClass
     Public Property Reference As ReferenceClass
        Get
             return myReference
         End Get
         Set(value As ReferenceClass)
             myReference = value
         End Set
     End Property

     Public Sub New(ByVal Reference As ReferenceClass)
         myReference = Reference
     End Sub

End Class

然后像这样使用它:

Public Class RuntimeOrSomething

     Public Shared myReference As ReferenceClass
     Public Shared ReadOnly Property Reference As ReferenceClass
         Get
             If myReference Is Nothing Then myReference = new ReferenceClass()
             return myReference
         End Get
     End Property

     Public Shared Function BooleanCheck() As Boolean
         Reference.BooleanValue = True
         Dim tempClass As New UsingClass(Reference)
         tempClass.Reference.BooleanValue = False

         Return (tempClass.Reference.BooleanValue = Reference.BooleanValue)
     End Sub

     Public Shared Sub DoNothing()
          Reference.BooleanValue = True
          Dim someBoolean As Boolean = BooleanCheck

          ' Now Reference.Booleanvalue is "False"
     End Sub

End Class

现在，函数 BooleanCheck 将始终返回 true，即使引用“按值”传递给新类 UsingClass，而不是引用。因此，不会创建类的副本，但 UsingClass 中的局部变量 myReference 仍然引用/指向 中的属性 Reference RuntimeOrSomething.

如何优雅地解释这一点？

Answer 1

引用指向对象的实例，但它不是对象的实例。复制该对象的方向不会创建另一个对象，而是创建另一个也指向同一对象的引用。