Android Service详解（二）第一个Service
Service中有四个重要函数：
public IBinder onBind(Intent arg0)； //必须实现，返回接口给Service public void onCreate()； //Service创建时调用 public void onStart(Intent intent,int startId)；//通过startService（）会调用 public void onDestroy()； //销毁时StopService()调用
通过StartActivity（）函数启动Service，当第一次调用时会分别调用onCreate()和onStart在()；
之后只会调用onStart()；
通过函数StopService()结束Service，会调用onDestroy()；
调用BindService()：当Service未创建时调用onCreate()和onBind()；当创建了只调用onBind()；
使用函数bindService()和函数unbindService()可以绑定和解除绑定
对已经绑定的Service调用bindService()无效，即多次调用bindService()和调用一次bindService()一样。 unbindService()只能使用一次，即对于一个绑定的Service，只能调用一次unbindService()，多次调用会产生错误
该函数原型为：
bindService(Intent,ServiceConnection,BIND_AUTO_CREATE);
ServiceConnection是一个服务连接类，必须实现以下两个函数：
public void onServiceConnected(ComponentName arg0, IBinder arg1)//连接成功时调用 public void onServiceDisconnected(ComponentName arg0) //连接失败时调用
示例如下：
private ServiceConnection conn=new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName arg0, IBinder arg1) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, "success", Toast.LENGTH_LONG).show();
Log.i("SERVICE","success");
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, "errer", Toast.LENGTH_LONG);
Log.i("SERVICE","errer");
}
Service实例：
MainActivity.java:
private ServiceConnection conn=new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName arg0, IBinder arg1) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, "success", Toast.LENGTH_LONG).show();
Log.i("SERVICE","success");
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, "errer", Toast.LENGTH_LONG);
Log.i("SERVICE","errer");
}
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button1=(Button)this.findViewById(R.id.btn1);
Button button2=(Button)this.findViewById(R.id.btn3);
Button button3=(Button)this.findViewById(R.id.btn4);
Button button4=(Button)this.findViewById(R.id.btn5);
button1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
startService(new Intent(MainActivity.this,NewService.class));
}
});
button2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
stopService(new Intent(MainActivity.this,NewService.class));
}
});
button3.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
bindService(new Intent(MainActivity.this,NewService.class),conn,BIND_AUTO_CREATE);
}
});
button4.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
unbindService(conn);
}
});
｝
NewService.java:
public class NewService extends Service {
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
Toast.makeText(NewService.this, "onBind", Toast.LENGTH_LONG).show();
Log.i("SERVICE","onbind");
return null;
}
public void onCreate() {
super.onCreate();
Log.i("SERVICE","oncreat");
Toast.makeText(NewService.this, "onCreat", Toast.LENGTH_LONG).show();
}
public void onStart(Intent intent,int startId) {
Log.i("SERVICE","onstart");
Toast.makeText(NewService.this, "onStart", Toast.LENGTH_LONG).show();
}
public void onDestroy() {
Log.i("SERVICE","ondestory");
Toast.makeText(NewService.this, "onDestory", Toast.LENGTH_LONG).show();
}
}
Activity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <Button android:id="@+id/btn1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="start"/> <Button android:id="@+id/btn3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="stop"/> <Button android:id="@+id/btn4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="bind"/> <Button android:id="@+id/btn5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="unbind"/> </LinearLayout>
AndroidManifest.xml增加：
<service android:name="com.example.new1.NewService"/>