几天来我一直在尝试理解为什么我的浏览器控制台上出现此错误，完整堆栈：
\nUnhandled Promise rejection: NG0202: This constructor is not compatible with Angular Dependency Injection because its dependency at index 0 of the parameter list is invalid.\nThis can happen if the dependency type is a primitive like a string or if an ancestor of this class is missing an Angular decorator.\n\nPlease check that 1) the type for the parameter at index 0 is correct and 2) the correct Angular decorators are defined for this class and its ancestors. ; Zone: …