除了以上精彩的回答:

结构是值类型。

它们永远不能被设置为“无”。

设置一个结构= Nothing，将其所有的值类型设置为默认值。

在以下情况下使用类:

它的身份很重要。结构在按值传递给方法时被隐式复制。 它将占用大量内存。 它的字段需要初始化式。 你需要从基类继承。 你需要多态行为;

在以下情况下使用结构:

It will act like a primitive type (int, long, byte, etc.). It must have a small memory footprint. You are calling a P/Invoke method that requires a structure to be passed in by value. You need to reduce the impact of garbage collection on application performance. Its fields need to be initialized only to their default values. This value would be zero for numeric types, false for Boolean types, and null for reference types. Note that in C# 6.0 structs can have a default constructor that can be used to initialize the struct’s fields to nondefault values. You do not need to inherit from a base class (other than ValueType, from which all structs inherit). You do not need polymorphic behavior.

当您需要值类型语义而不是引用类型时，请使用结构。结构体是按值复制的，所以要小心!

另见以前的问题，例如:

.NET中struct和class的区别是什么?

正如@Simon所说，结构体提供了“值类型”语义，所以如果你需要类似于内置数据类型的行为，可以使用结构体。由于结构体是通过复制传递的，所以要确保它们的大小很小，大约16字节。

当我想要将几个值组合在一起以从方法调用中传递内容时，我总是使用结构体，但在读取这些值之后，我将不需要将它用于任何事情。只是为了保持干净。我倾向于将struct中的东西视为“扔掉的”，而将类中的东西视为更有用和“功能性的”

嗯…

I wouldn't use garbage collection as an argument for/against the use of structs vs classes. The managed heap works much like a stack - creating an object just puts it at the top of the heap, which is almost as fast as allocating on the stack. Additionally, if an object is short-lived and does not survive a GC cycle, deallocation is free as the GC only works with memory that's still accessible. (Search MSDN, there's a series of articles on .NET memory management, I'm just too lazy to go dig for them).

大多数情况下，我使用结构体时，都会后悔这样做，因为我后来发现使用引用语义会让事情更简单一些。

无论如何，上面的MSDN文章中的这四点似乎是一个很好的指导方针。