vb.net Class 属性的默认值
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Default values of Class properties
提问by user432209
I have a class, it looks like this:
我有一堂课，它看起来像这样：
Public Class DataPoint
Private _data As Integer
Private _locInText As Integer
Private _searchValue As String
Property Data As Integer
Get
Return _data
End Get
Set(value As Integer)
_data = value
End Set
End Property
Property LocInText As Integer
Get
Return _locInText
End Get
Set(value As Integer)
_locInText = value
End Set
End Property
Property SearchValue As String
Get
Return _searchValue
End Get
Set(value As String)
_searchValue = value
End Set
End Property
End Class
I then create another class using this class.
然后我使用这个类创建另一个类。
Public Class PaintData
Public Time As TimeSpan
Public Color As DataPoint
Public Job As New DataPoint
Public MaxCurrent As New DataPoint
End Class
I want to create default values of some of the properties, namly SearchValueand LocInText. To me, it makes sense to do this inside the class definition, because these are essentially constants.
我想创建一些属性的默认值，例如SearchValue和LocInText. 对我来说，在类定义中这样做是有意义的，因为这些本质上是常量。
Q1. Should I be doing it this way? If not, what is the proper technique.
一季度。我应该这样做吗？如果没有，正确的技术是什么。
Q2. I can't get the syntax right. Can you help?
Q2。我的语法不正确。你能帮我吗？
Public Class PaintData
Public Time As TimeSpan
Public Color As DataPoint
Public Job As New DataPoint
Public MaxCurrent As New DataPoint
Color.LocInText = 4 '<----Declaration expected failure because I'm not in a method
Job.LocInText = 5 '<----Declaration expected failure because I'm not in a method
End Class
Thanks all
谢谢大家
回答by James Thorpe
Give DataPointa constructor:
给DataPoint一个构造函数：
Public Class DataPoint
Private _data As Integer
Private _locInText As Integer
Private _searchValue As String
Public Sub New(locInText as Integer)
_locInText = locInText
End Sub
'...
End Class
And use that:
并使用它：
Public Class PaintData
Public Time As TimeSpan
Public Color As New DataPoint(4)
Public Job As New DataPoint(5)
Public MaxCurrent As New DataPoint(6)
End Class
Alternatively you could use
或者你可以使用
Public Property Color As DataPoint = New DataPoint With {.LocInText = 4}
in your class definition. This syntax is arguably more readable than the constructor syntax.
在你的类定义中。这种语法可以说比构造函数语法更具可读性。
