VB.Net Property? or Method? - 属性还是方法

在VB.net中，我们有属性这一概念，通常的表达格式是：

 1   Private _myProperty As String
 2   Property myProperty() As String
 3     Get
 4       Return _myProperty
 5     End Get
 6     Set(ByVal value As String)
 7       _myProperty = value
 8     End Set
 9   End Property
10  

但是在特殊的情况下，我们可能需要一个属性去设置多个值，这时候我们就会考虑到使用方法，传递多个参数。在VB.Net中就可以省略这个步骤，因为VB.Net属性既是方法，我们可以混淆，如下定义：

 1   Private _LastName As String
 2   Private _FirstName As String
 3   Private _FullName As String
 4   Property Name(Optional ByVal FirstName As String = "", Optional ByVal LastName As String = "") As String
 5     Get
 6       Return _FullName + " (FirstName: " + _FirstName + " LastName: " + _LastName + ")"
 7     End Get
 8     Set(ByVal value As String)
 9       _FirstName = FirstName
10       _LastName = LastName
11       _FullName = value
12     End Set
13   End Property

怎么去使用？简单，既当方法调用，又当属性赋值： 

1     Dim obj As myCustomClass = New myCustomClass
2     obj.Name("Tom", "Smith") = "Jim John"
3     MessageBox.Show(obj.Name)

image

VB.Net在识别属性时其实内部他将属性的调用转换成了方法，上面这段代码实质上是对

 

obj.Name(byVal value As String, Optional ByVal FirstName As String = "", Optional ByVal LastName As String = "")

 

这样我们就可以混淆实现既是方法又是属性的功能。

 

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posted @ 2010-05-11 23:36  Jarrey  阅读(4652)  评论(2)  编辑  收藏  举报