如何从Android中的另一个活动调用MapActivity的方法？

Question

I am working on an Android application that based on Google Maps API. I have a refresh() method to refresh my MapActivity . I want to call the refresh() method to refresh the map after I managed my POIs from another activity.

MapActivity.refresh();

This is my refresh() method:

public void refresh() {
    Intent intent = getIntent();
    finish();
    startActivity(intent);
}

I know I can call this method from other activities if it is static . So, I made this following change:

public static void refresh() {
    Intent intent = getIntent();
    finish();
    startActivity(intent);
}

After that, I get this message:

Non-static method 'getIntent()' cannot be referenced from a static context

Is there another way to refresh the map?

Answer 1

After I read the useful comments, I made this mapReset() method:

public void mapReset() {
    map.clear();
    addAllMarkers();
    //...
}

I add this method into the ChildEventListener and the map will be reset after I managed the POIs. This solves my problem.

poiFirebase.addChildEventListener(new ChildEventListener() {
    @Override
    public void onChildAdded(DataSnapshot dataSnapshot, String s) {
        //...
        mapReset();
    }

    @Override
    public void onChildChanged(DataSnapshot dataSnapshot, String s) {
        //...
        mapReset();
    }

    @Override
    public void onChildRemoved(DataSnapshot dataSnapshot) {
        //...
        mapReset();
    }

    @Override
    public void onChildMoved(DataSnapshot dataSnapshot, String s) {
        //...
        mapReset();
    }

    @Override
    public void onCancelled(FirebaseError firebaseError) {
        //...
    }
});

Answer 2

A static method is defined once , and is not related to a class instance. So you can't modify a class instance with it. What you could do is store your MapActivity in a class as a static member, for example:

public class World {
    public static MapActivity myMap;
    ...
}

Then you can access your map like this:

World.myMap.refresh();

The difference being that your whole MapActivity is considered a static member, but once you called World.myMap , you have a class instance.