Service的onServiceConnected没有被调用

Service是一种运行在后台的服务，一般很少与用户交互，所以没有可视化界面。

我们可以通过startService() 或者使用bindService()方法来绑定一个存在的service。

bindService是异步调用和Service进行绑定, 如果绑定成功, 则会调用ServiceConnection的onServiceConnected

当调用bindService方法后就会回调Activity的onServiceConnected，在这个方法中会向Activity中传递一个IBinder的实例，Acitity需要保存这个实例

在Service中需要创建一个实现IBinder的内部类(这个内部类不一定在Service中实现，但必须在Service中创建它)。

在OnBind（）方法中需返回一个IBinder实例，不然onServiceConnected方法不会调用。

</pre><pre name="code" class="java"> import android.app.Activity; import android.content.ComponentName; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.IBinder; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Toast; public class ServiceActivity extends Activity { /** Called when the activity is first created. */ private Button start; private Button stop; private Button bind; private Button unbind; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); start =(Button) findViewById(R.id.start); stop = (Button) findViewById(R.id.stop); bind = (Button) findViewById(R.id.bind); unbind = (Button) findViewById(R.id.unbind); //启动一个service start.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent = new Intent(); System.out.println("start...."); intent.setAction("com.shao.service.action.MyService"); startService(intent); } }); //结束一个service stop.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent = new Intent(); System.out.println("stop...."); intent.setAction("com.shao.service.action.MyService"); stopService(intent); } }); //绑定一个service bind.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent = new Intent(); System.out.println("bind.."); intent.setAction("com.shao.service.action.MyService"); bindService(intent, conn, BIND_AUTO_CREATE); } }); //解除绑定的service unbind.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent = new Intent(); System.out.println("unbind.."); intent.setAction("com.shao.service.action.MyService"); unbindService(conn); } }); } private ServiceConnection conn = new ServiceConnection() { @Override public void onServiceDisconnected(ComponentName arg0) { // TODO Auto-generated method stub Toast.makeText(ServiceActivity.this,"disconn successful" ,Toast.LENGTH_LONG); } @Override public void onServiceConnected(ComponentName name, IBinder service) { // TODO Auto-generated method stub Toast.makeText(ServiceActivity.this,"conn successful" ,Toast.LENGTH_LONG); } }; }

</pre><p></p><p>MyService文件：</p><p></p><pre name="code" class="java"> import android.app.Service; import android.content.Intent; import android.os.Binder; import android.os.IBinder; import android.os.Parcel; import android.widget.Toast; public class MyService extends Service { @Override public IBinder onBind(Intent intent) { // TODO Auto-generated method stub System.out.println("onBind....."); IBinder result = null; if ( null == result ) result = new MyBinder() ; Toast.makeText(this, "onBind",Toast.LENGTH_LONG); return result; } @Override public void onCreate() { // TODO Auto-generated method stub super.onCreate(); System.out.println("onCreate....."); Toast.makeText(this, "onCreate",Toast.LENGTH_LONG); } @Override public void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); System.out.println("onDestory....."); Toast.makeText(this, "onDestroy",Toast.LENGTH_LONG); } @Override public void onStart(Intent intent, int startId) { // TODO Auto-generated method stub super.onStart(intent, startId); System.out.println("onStart..."); Toast.makeText(this, "onStart",Toast.LENGTH_LONG); } public class MyBinder extends Binder { //此方法是为了可以在Acitity中获得服务的实例 public MyService getService() { return MyService.this; } } }

Service需在mainifest文件中声明:

   <service android:name="MyService">

                 <intent-filter>
                <action android:name="com.shao.service.action.MyService"/>
              </intent-filter>
             </service>