我正在看一些同事写的代码和我预期会发生的代码.这是代码:
public class SingletonClass { private static readonly SingletonClass _instance = new SingletonClass(); public static SingletonClass Instance { get { return _instance; } } private SingletonClass() { //non static properties are set here this.connectionString = "bla" this.created = System.DateTime.Now; } }
在另一堂课中,我希望能够做到:
private SingletonClass sc = SingletonClass.Instance.Instance.Instance.Instance.Instance.Instance;
它引用该类的相同实例.发生的事情是我只能有一个.实例.我没想到的东西.如果Instance属性返回一个SingletonClass类,为什么我不能在返回的类上调用Instance属性,依此类推?
解决方法
If the Instance property returns a SingletonClass class,why can’t I call the Instance property on that returned class and so on and so on?
因为您只能通过SingletonClass类型访问.Instance,而不能通过该类型的实例访问.Instance.
由于Instance是静态的,您必须通过以下类型访问它:
SingletonInstance inst = SingletonInstance.Instance; // Access via type // This fails,because you're accessing it via an instance // inst.Instance
当你试图链接这些时,你实际上是这样做的:
SingletonInstance temp = SingletonInstance.Instance; // Access via type // ***** BAD CODE BELOW **** // This fails at compile time,since you're trying to access via an instance SingletonInstance temp2 = temp.Instance;