如何在iOS Attribute Inspector中指定两个线条标签(How to specify two line label in iOS Attribute Inspector)

 只有方法才能overridable字段，字段只能隐藏或不隐藏。 this实际上是指当前的Object ，它在Parent#getName()方法中是Parent#getName()类型，这样它将获得在Parent定义的变量名的值，或者可能是父类，而不是像Child这样的子类。 
 
 这是一个简单的代码片段，显示了这个想法： 
 
Child child = new Child();
// Show the variable name of the class Child
System.out.println(child.name);
// Show the variable name of the class Parent which is what this.name 
// does in the getName method
System.out.println(((Parent)child).name);
 
 输出： 
 
Child
Parent

Fields are not overridable only methods are, the fields can only be hidden or not. this actually refers to the current Object which is of type Parent in the method Parent#getName() such that it will get the value of the variable name defined in Parent or potentially a parent class but not in a sub class like Child. 
 
Here is a simple code snippet that shows the idea:
 
Child child = new Child();
// Show the variable name of the class Child
System.out.println(child.name);
// Show the variable name of the class Parent which is what this.name 
// does in the getName method
System.out.println(((Parent)child).name);
 
Output:
 
Child
Parent