Question

我使用观察者模式

最近，在我的主要课程中，

MainActivity.class

static private AutoObservable observable;   //global variable 
private Agency agency = null; //global variable

@Override
protected void onStart() {
   super.onStart();
   observable = agency;
   observable.addObserver(new Observerclass(agency.RoomName()));
}

AutoObservable.class

public class AutoObservable extends Observable {
@Override
public void notifyObservers(Object data) {
    super.setChanged();
    super.notifyObservers(data);
    super.clearChanged();
}
}

Observerclass.class

public class Observerclass implements Observer {
   private final String roomName;
   public Observerclass(String roomName) {
         this.roomName = roomName;
   }

   @Override
   public void update(Observable observable, Object o) {
      . . .   // not work ..
   }

或许，许可问题？.. 请给我建议。

Answer 1

您不必覆盖notifyObservers()，因此，请从AutoObservable

中删除此代码块

@Override
public void notifyObservers(Object data) {
    super.setChanged();
    super.notifyObservers(data);
    super.clearChanged();
}

相反，请执行AutoObservable.java

之类的操作

public void onSomeEvent() {
    setChanged();
    notifyObservers(data);
}

并且，从MainActivity调用Observer实例

observable.onSomeEvent();

android Observer方法更新不起作用

1 个答案: