Android之Service启动方式

Service启动方式介绍

一种是通过这种方式启动

Intent intent = new Intent();
intent.setClass(MainActivity.this, FirstService.class);
MainActivity.this.startService(intent);

还有一种是通过这种方式启动

private ServiceConnection conn = new ServiceConnection() {

@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub

}

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// TODO Auto-generated method stub
}
};

##
<span style="white-space:pre">	</span>Intent intent = new Intent(SecondActivity.this, BindService.class);
bindService(intent, conn, Context.BIND_AUTO_CREATE);

使用bind方式启动service只能启动一次，而通过startService方式启动service可以启动多次，但是只有第一次会调用onCreate()方法。bind方式启动的service会随activity的关闭而关闭或者通过unbindService()关闭，但是通过startService的方式启动的service不会随activity关闭而关闭，需要调用stopService方法获者stopSelf关闭。
注：线程开启了之后还可以与activity绑定，绑定了之后也可以通过startService()启动
Service生命周期介绍
1-1通过startService()启动的service调用生命周期的过程是
onCreate()

onStartCommand()

onStart()

1-2通过stopService()关闭的service调用生命周期的过程是

onDestroy()

2-1通过bind方式启动的service调用生命周期的过程是

onCreate()

onBind()

2-2通过bind方式关闭的service调用生命周期的过程是

onUnbind()

onDestroy()

接下来请看一个例子

MainActivity.class

public class MainActivity extends Activity {
private Button start ;
private Button stop ;
private Button next;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
start = (Button) findViewById(R.id.start);
stop = (Button) findViewById(R.id.stop);
next = (Button) findViewById(R.id.next);
next.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO 跳转到另一个activity
Intent intent = new Intent();
intent.setClass(MainActivity.this, BindActivity.class);
startActivity(intent);
}
});
start.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO 启动service，可以启动多次，但是只有第一次会调用onCreate方法
Intent intent = new Intent();
intent.setClass(MainActivity.this, StartService.class);
MainActivity.this.startService(intent);
}
});
stop.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO 关闭service
Intent intent = new Intent();
intent.setClass(MainActivity.this, StartService.class);
MainActivity.this.stopService(intent);
}
});
}
}

FirstService.class

public class StartService extends Service {

@Override
public IBinder onBind(Intent intent) {
Log.e("TAG", "onBind");
return null;
}

/**
* 第一次启动调用
*/
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();

Log.e("TAG", "onCreate");
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
Log.e("TAG", "onStartCommand,startId=" + startId);
return super.onStartCommand(intent, flags, startId);
}

@Override
@Deprecated
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
super.onStart(intent, startId);
Log.e("TAG", "onStart");
}

@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
Log.e("TAG", "onDestroy");
}

@Override
public void onLowMemory() {
// TODO Auto-generated method stub
super.onLowMemory();
Log.e("TAG", "onLowMemory");
}

@Override
public void onTrimMemory(int level) {
// TODO Auto-generated method stub
super.onTrimMemory(level);
Log.e("TAG", "onTrimMemory");
}

@Override
public boolean onUnbind(Intent intent) {
// TODO Auto-generated method stub
Log.e("TAG", "onUnbind");
return super.onUnbind(intent);
}

@Override
public void onRebind(Intent intent) {
// TODO Auto-generated method stub
super.onRebind(intent);
Log.e("TAG", "onRebind");
}

/**
* 从后台移除会调用这个方法
*/
@Override
public void onTaskRemoved(Intent rootIntent) {
// TODO Auto-generated method stub
super.onTaskRemoved(rootIntent);
Log.e("TAG", "onTaskRemoved");
}

}

BindActivity.class

public class BindActivity extends Activity {
private Button bind;
private Button unBind;
private Button callMethod;
private BindService bindService;
private ServiceConnection conn = new ServiceConnection() {

@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub

}

/**
* 此处的IBinder是service中onBind()方法返回的
*/
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// TODO Auto-generated method stub
MyBinder binder = (MyBinder) service;
bindService = binder.getService();
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bind = (Button) findViewById(R.id.start);
unBind = (Button) findViewById(R.id.stop);
callMethod = (Button) findViewById(R.id.next);
unBind.setText("解绑service");
bind.setText("绑定service");
callMethod.setText("调用service方法");

bind.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
bindService();
}
});
unBind.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
unBind();
}
});

callMethod.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
bindService.serviceMethod();
}
});
}

private void bindService() {
Intent intent = new Intent();
intent.putExtra("haha", "haha");
intent.setClass(BindActivity.this, BindService.class);
bindService(intent, conn, Context.BIND_AUTO_CREATE);
}

private void unBind() {
unbindService(conn);
}

@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
}

BindService.class

public class BindService extends Service {

/**
* 此处的intent是从bindService方法中传过来的
*/
@Override
public IBinder onBind(Intent intent) {
Log.e("TAG", "onBind,intent="+intent.getStringExtra("haha"));
return myBinder;
}

@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();

Log.e("TAG", "onCreate");
}

public void serviceMethod() {
Log.e("TAG", "调用serviceMethod()");
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
Log.e("TAG", "onStartCommand,startId=" + startId);
return super.onStartCommand(intent, flags, startId);
}

@Override
@Deprecated
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
super.onStart(intent, startId);
Log.e("TAG", "onStart");
}

@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
Log.e("TAG", "onDestroy");
}

@Override
public void onLowMemory() {
// TODO Auto-generated method stub
super.onLowMemory();
Log.e("TAG", "onLowMemory");
}

@Override
public void onTrimMemory(int level) {
// TODO Auto-generated method stub
super.onTrimMemory(level);
Log.e("TAG", "onTrimMemory");
}

@Override
public boolean onUnbind(Intent intent) {
// TODO Auto-generated method stub
Log.e("TAG", "onUnbind");
return super.onUnbind(intent);
}

@Override
public void onRebind(Intent intent) {
// TODO Auto-generated method stub
super.onRebind(intent);
Log.e("TAG", "onRebind");
}

@Override
public void onTaskRemoved(Intent rootIntent) {
// TODO Auto-generated method stub
super.onTaskRemoved(rootIntent);
Log.e("TAG", "onTaskRemoved");
}

public class MyBinder extends Binder {

public BindService getService() {
return BindService.this;
}
}

private MyBinder myBinder = new MyBinder();

}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.servicetest.MainActivity" >

<Button
android:id="@+id/start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开启service" />

<Button
android:id="@+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="关闭service" />

<Button
android:id="@+id/next"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="下一个" />

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.servicetest"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="19" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".BindActivity"
android:label="@string/app_name" >
</activity>

<service
android:name=".StartService"
android:label="@string/app_name" >
</service>
<service
android:name=".BindService"
android:label="@string/app_name" >
</service>
</application>

</manifest>