Question

我有一个活动，它填充框架布局和 MapFragment 。地图标记应该每隔几分钟更新一次，所以我想我可以使用服务来生成http请求。

问题是，这项服务（尚未实施）如何能够传达或更新我的MapFragment UI以及一些主要活动的用户界面？

Answer 1

您可以通过注册广播接收器来更新您的活动/片段。

Answer 2

您可以通过服务接收活动的更新，请参阅此计数器示例以获取帮助。

<强> CounterUpdates.java

package yourPackage;

public class CounterUpdates {
    private static CounterUpdates mInstance;
    private ICounterUpdates mListener;

    private CounterUpdates() {}

    public static CounterUpdates getInstance() {
        if(mInstance == null) {
            mInstance = new CounterUpdates();
        }
        return mInstance;
    }

    public void setListener(ICounterUpdates listener) {
        mListener = listener;
    }

    public void onCountUpdate(int count) {
        if(mListener != null) {
            mListener.onCountUpdate(count);
        }
    }


    // Definition of location updates interface
    public interface ICounterUpdates {
        public void onCountUpdate(int count);
    }
}

<强> CounterService.java

package yourPackage;

import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;

public class CounterService extends Service {

    private Handler mHandler = new Handler();
    private int mCount = 0;
    private static final int INTERVAL = 500;
    private Runnable mRunnableCounter = new Runnable() {
        @Override
        public void run() {
            deliverResults(++mCount);
            mHandler.postDelayed(this, INTERVAL);
        }
    };


    @Override
    public int onStartCommand(final Intent intent, final int flags, final int startId) {
        startCounterThread();
        return START_STICKY;
    }


    private void startCounterThread() {
        mCount = 0;
        mHandler.postDelayed(mRunnableCounter, INTERVAL);
    }

    private void stopCounterThread() {
        mHandler.removeCallbacks(mRunnableCounter);
    }



    public static void deliverResults(int count) {
        CounterUpdates.getInstance().onCountUpdate(count);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        stopCounterThread();
    }

    @Override
    public IBinder onBind(final Intent intent) {
        return null;
    }
}

AndroidManifest.xml （注册您的服务）

<service android:name="yourPackage.CounterService" />

启动服务使用此代码：

startService(new Intent(this, CounterService.class));

<强> YourActivity.java

public class YourActivity extends Activity implements CounterUpdates.ICounterUpdates {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_layout);

        CounterUpdates.getInstance().setListener(this);
    }

    @Override
    public void onCountUpdate(int count) {
        ((TextView) findViewById(R.id.textView)).setText("Count: " + count);
    }

}

我希望它能奏效，祝你好运：）

服务和主要活动沟通

2 个答案: