bindService不是瞬时的吗还是？现在空指针异常。。。

public class MainActivity extends Activity { 


 MySer mySer; 


 ServiceConnection conn = new ServiceConnection() { 


 @Override 
 public void onServiceDisconnected(ComponentName name) { 
 mySer = null; 


 } 


 @Override 
 public void onServiceConnected(ComponentName name, IBinder service) { 
 mySer = ((MySer.MyBinder) service).getSer(); 
 System.out.println("-----绑定"); 
 } 
 }; 


 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.activity_main); 
 bindService(new Intent(this, MySer.class), conn, 
 Context.BIND_AUTO_CREATE); 
 startService(new Intent(this, MySer.class)); 


 findViewById(R.id.button1).setOnClickListener(new OnClickListener() { 


 @Override 
 public void onClick(View v) { 
 ((TextView) findViewById(R.id.textView1)).setText("开始"); 
 mySer.startD(); 
 } 
 }); 
 } 


 }