来自另一个活动的Android调用方法

Question

How would I call a method from a different activity? In my main activity, I have a button that shows a dialog to set the difficulty level of the game. Then you click start game which starts a new activity containing a view with all the game information. I need to send the difficulty level chosen to the other activity but cannot seem to figure out how to.

Answer 1

You could put it in the extras with the intent:

Intent StartGame = new Intent(this, StartGame.class);
StartGame.putExtra("difficulty", difficultyLevel);
startActivity(StartGame);

Then in your StartGame.class you can retrive it like this(assuming its a string):

Bundle extras = getIntent().getExtras();
if (extras != null) {
    String difficulty= extras.getString("difficulty");
}

Answer 2

Well I don't know how sound my solution is but I created a myApplication class which sub classes the Application class .

This holds the reference to the activity I wanted to call

import android.app.Application;

public class myApplication extends Application {
    public PostAndViewActivity pv;
}

When the PostAndViewActivity calls the oncreate is sets the pv to point to itself.

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ((myApplication) getApplication()).pv = this;

Then when I want to call the method I want I just use code like this:

((myApplication) getApplication()).pv.refreshYourself();

Perhaps a bit hacky but it works..... I welcome some critisism for this ;-)