我是VB.NET的新手,并且搜索一个复制DataRow行为的方法.
在VB.NET中我可以写这样的东西：
在VB.NET中我可以写这样的东西：
Dim table As New DataTable
'assume the table gets initialized
table.Rows(0)("a value") = "another value"
现在如何用括号访问班级成员？我以为我可以重载()运算符,但这似乎不是答案.
它不是一个过载运算符,这被称为
default property.
原文链接：https://www.f2er.com/vb/255051.html“A class,structure,or interface can designate at most one of its properties as the default property,provided that property takes at least one parameter. If code makes a reference to a class or structure without specifying a member,Visual Basic resolves that reference to the default property.” – MSDN –
DataRowCollection类和DataRow类都有一个名为Item的默认属性.
| |
table.Rows.Item(0).Item("a value") = "another value"
这允许您在不指定Item成员的情况下编写代码：
table.Rows(0)("a value") = "another value"
Public Class Foo
Default Public Property Test(index As Integer) As String
Get
Return Me.items(index)
End Get
Set(value As String)
Me.items(index) = value
End Set
End Property
Private ReadOnly items As String() = New String(2) {"a","b","c"}
End Class
Dim f As New Foo() Dim a As String = f(0) f(0) = "A"
鉴于上面的示例,您可以使用字符串类的默认属性来获取指定位置的字符.
f(0) = "abc" Dim c As Char = f(0)(1) '<- "b" | f.Test(0).Chars(1)