C#vs VB.NET - 处理null结构

Question

我遇到了这个,并想知道是否有人可以解释为什么这在VB.NET中工作,我希望它会失败,就像在C#中一样

//The C# Version

struct Person {
    public string name;
}
...
Person someone = null; //Nope! Can't do that!!
Person? someoneElse = null; //No problem, just like expected

但是在VB.NET中...

Structure Person
    Public name As String
End Structure
...
Dim someone As Person = Nothing 'Wha? this is okay?

没有什么不同于null(Nothing!= null - LOL？),或者这只是处理两种语言之间相同情况的不同方式？

为什么或两者之间的处理方式不同,这使得一个可以在一个,而不是另一个？

[更新]

鉴于一些评论,我更多地搞砸了......如果你想在VB.NET中允许某些东西为null,那么好像你真的必须使用Nullable ...例如...

'This is false - It is still a person'
Dim someone As Person = Nothing
Dim isSomeoneNull As Boolean = someone.Equals(Nothing) 'false'

'This is true - the result is actually nullable now'
Dim someoneElse As Nullable(Of Person) = Nothing
Dim isSomeoneElseNull As Boolean = someoneElse.Equals(Nothing) 'true'

太奇怪了......

Answer 1

如果我没记错的话,VB中的'Nothing'意味着"默认值".对于值类型,对于引用类型,这是null的默认值.因此,不给结构赋予任何东西,完全没有问题.

Answer 2

Nothing大致相当于default(T)相关类型.(刚检查过,对于字符串也是如此 - 即Nothing在字符串的上下文中是空引用.)