android - 将数据从类传递到 MainActivity

Question

我正在 onCreate() 中从 MainActivity 启动一个服务 TrackingService。从 TrackingService 我将 JSONString 传递给 PostData 类。然后我从服务器收到带有方向，路线的响应。我想将这些值传递给 MainActivity，但我没有在 MainActivity 中获取它们。方向和路线都有值，并且 onPostExecute() 正在被调用，并且方法中的条件 if (route != 0) {} 正在输入，但 'onNewIntent() MainActivity 中的方法未被调用。如何修复它以从 PostData 类获取 MainActivity 中的方向和路线？

MainActivity 类:

public class MainActivity extends ActionBarActivity implements
        AsyncTaskCallback {

    private static Context context;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
                        Intent i = new Intent(this, TrackingService.class);
        startService(i);
      }
    public static Context getAppContext() {
        return context;
    }
    @Override
protected void onNewIntent(Intent intent) {

    super.onNewIntent(intent);
    Bundle extras = getIntent().getExtras();

    if (extras != null && extras.containsKey("dirtRout")) {
        String directRoute = extras.getString("dirtRout");

        String[] split = directRoute.split(",");
        String direc = split[0];
        String route1 = split[1];
        boolean test = true;
        if (test) {
            test = false;
            System.out.println("test f MainActivity: " + direc + ": "
                    + route1);

            tvD = (TextView) findViewById(R.id.textDirect);
            tvD.setText(direc);
            tvR = (TextView) findViewById(R.id.textRoute);
            tvR.setText(route1);
        }
    }

}
}

跟踪服务类:

public class TrackingService extends Service implements AsyncTaskCallback,
        LocationListener {
  ...
    @Override
    public void onLocationChanged(Location location) {
                        PostData sender = new PostData(TrackingService.this);
                sender.post_data(jSONString, this);
 }
  }

PostData 类:

public class PostData {
    String jSONString;
    private AsyncTaskCallback callback;
    public PostData(AsyncTaskCallback callback) {
        this.callback = callback;
    }
    class MyAsyncTask extends AsyncTask<String, Integer, ArrayList<Integer>> {
        int route;
        String direction;
  .....
        @Override
        protected ArrayList<Integer> doInBackground(String... params) {

                ......
                                Gson gson = new Gson();
                JSONStore data = gson.fromJson(sb.toString(), JSONStore.class);

                route = data.getRoute();
                direction = data.getDirection();
  }
        protected void onPostExecute(ArrayList<Integer>  result) {
                            if (route != 0) {
                                String directRoute = direction + "," +Integer.toString(route);             
                Intent intent = new Intent(MainActivity.getAppContext(), MainActivity.class);
                intent.putExtra("dirtRout", directRoute);
      }

  }
}

Answer 1

创建 Intent 后您不会开始 Activity 。从应用程序获取当前的 Activity 并调用 startActivity 方法。