IntentService的优点

IntentService会创建单独的线程处理所有的Intent请求，

会处理onHandleIntent方法实现的代码，

隐藏开发者无须处理多线程问题，

当所有请求处理完成后，IntentService会自动停止

Action的使用

Action其实就是一个字符串，可以起到一个标识的作用

BroadcastReceiver的使用

BroadcastReceiver本质是一个监听器，有自己的进程

重写onReceive方法即可，但是在该方法里面不要执行耗时的操作，否则会ANR

发送

创建Intent

设置Action

putExtra

send发送

接收

实现onReceive方法

在AndroidManifest内增加配置

BroadcastReceiver

其他

开机自动运行的Service

第一步

动态注册广播

broadcastReceiver = new MyReceiver();

IntentFilter intentFilter = new IntentFilter();

intentFilter.addAction("com.example.space.text2.action.MSGTEXT");

//这个Action的作用是当发送为该Action的广播时，

该MyReceiver类的onReceive方法将会接收到并处理

registerReceiver(broadcastReceiver,intentFilter);

第二步

在Activity中添加一个UI组件，比如按钮

为按钮添加监听器

在该监听器内启动IntentService

Intent intent = new Intent(FinsihActivity.this,TextIntentService.class);

intent.setAction("com.example.space.text2.action.MSGFINSIH");

//设置该Action以便IntentService接收到Intent，

判断是哪个Action,如果是这个Action话，就进行相应处理

intent.putExtra("finish","这是finishactivity发送的消息");

FinsihActivity.this.startService(intent);

第三步

添加一个IntentService.java类，可以使用Android Studio的自动生成

注释掉没有用的代码

但是一定要保留protected void onHandleIntent(Intent intent) 和

public TextIntentService() {

super("TextIntentService");

}

方法

在protected void onHandleIntent(Intent intent) 方法中进行后台任务的处理即可

protected void onHandleIntent(Intent intent) {

if (intent != null) {

final String action = intent.getAction();

if (ACTION_MSGFINSIH.equals(action)) {

String param1 = intent.getStringExtra("finish");

Intent intent1 = new Intent(ACTION_MSGTEXT);

//此处ACTION_MSGTEXT等于"com.example.space.text2.action.MSGTEXT"，

生成包含该Action的Intent后，就可以使用sendBroadcast发送广播了，

之后自己定义的MyReceiver类的onReceive方法将会接收到并处理

intent1.putExtra("msg",param1+",IntentService收到并且广播了出去");

sendBroadcast(intent1);

}

}

}

第四步

在自己定义的MyReceiver类的onReceive方法将会接收到并处理收到的intent

这个自己定义的MyReceiver类最好以内部类的形式写在使用该广播的Activity中，

这样就可以使用该Activity的UI组件了，

即可实现把后台服务进程中的数据更新在UI线程中的UI组件中

//内部类

public class MyReceiver extends BroadcastReceiver {

@Override

public void onReceive(Context context, Intent intent) {

// TODO: This method is called when the BroadcastReceiver is receiving

// an Intent broadcast.

Toast.makeText(getApplicationContext(), intent.getStringExtra("msg"),

Toast.LENGTH_SHORT).show();

//throw new UnsupportedOperationException("Not yet implemented");

//注意，该句是自动生成的，

一定要注释掉，否则程序会崩溃重启，

无法显示出后台服务通过广播改变前台UI的效果

}

}

完整代码

第一个是Activity

public class FinsihActivity extends AppCompatActivity {

BroadcastReceiver broadcastReceiver;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_finsih);

//第一步：注册广播，绑定广播和action

try

{

broadcastReceiver = new MyReceiver();

IntentFilter intentFilter = new IntentFilter();

intentFilter.addAction("com.example.space.text2.action.MSGTEXT");

registerReceiver(broadcastReceiver,intentFilter);

Log.i("mss","registerReceiver(broadcastReceiver,intentFilter);");

}

catch (ParcelFormatException e)

{

Log.i("mss","catch");

}

Button button = (Button)super.findViewById(R.id.button2);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

//第二步：开始IntentService

try

{

Intent intent = new Intent(FinsihActivity.this,TextIntentService.class);

Log.i("mss","Intent intent = new Intent(FinsihActivity.this,TextIntentService.class)");

intent.setAction("com.example.space.text2.action.MSGFINSIH");

intent.putExtra("finish","这是finishactivity发送的消息");

FinsihActivity.this.startService(intent);

Log.i("mss","FinsihActivity.this.startService(intent);");

Toast.makeText(getApplicationContext(), "startService(intent)", Toast.LENGTH_SHORT).show();

}

catch(ParcelFormatException e)

{

Log.i("mss","catch");

}

}

});

}

//内部类

public class MyReceiver extends BroadcastReceiver {

@Override

public void onReceive(Context context, Intent intent) {

// TODO: This method is called when the BroadcastReceiver is receiving

// an Intent broadcast.

//

Toast.makeText(getApplicationContext(), intent.getStringExtra("msg"), Toast.LENGTH_SHORT).show();

// TextView textView = (TextView)FinsihActivity.super.findViewById(R.id.textView13);

// textView.setText(""+intent.getStringExtra("msg"));

//throw new UnsupportedOperationException("Not yet implemented");

}

}

}

第二个是IntentService

public class TextIntentService extends IntentService {

// TODO: Rename actions, choose action names that describe tasks that this

// IntentService can perform, e.g. ACTION_FETCH_NEW_ITEMS

private static final String ACTION_MSGTEXT = "com.example.space.text2.action.MSGTEXT";

private static final String ACTION_MSGFINSIH = "com.example.space.text2.action.MSGFINSIH";

private static final String ACTION_BAZ = "com.example.space.text2.action.BAZ";

// TODO: Rename parameters

public TextIntentService() {

super("TextIntentService");

}

// /**

// * Starts this service to perform action Foo with the given parameters. If

// * the service is already performing a task this action will be queued.

// *

// * @see IntentService

// */

// // TODO: Customize helper method

// public static void startActionFoo(Context context, String param1, String param2) {

// Intent intent = new Intent(context, TextIntentService.class);

// intent.setAction(ACTION_MSGTEXT);

// intent.putExtra(EXTRA_PARAM1, param1);

// intent.putExtra(EXTRA_PARAM2, param2);

// context.startService(intent);

// }

//

// /**

// * Starts this service to perform action Baz with the given parameters. If

// * the service is already performing a task this action will be queued.

// *

// * @see IntentService

// */

// // TODO: Customize helper method

// public static void startActionBaz(Context context, String param1, String param2) {

// Intent intent = new Intent(context, TextIntentService.class);

// intent.setAction(ACTION_BAZ);

// intent.putExtra(EXTRA_PARAM1, param1);

// intent.putExtra(EXTRA_PARAM2, param2);

// context.startService(intent);

// }

@Override

protected void onHandleIntent(Intent intent) {

Log.i("mss","onHandleIntent");

if (intent != null) {

final String action = intent.getAction();

if (ACTION_MSGFINSIH.equals(action)) {

Log.i("mss","ACTION_MSGFINSIH.equals(action)");

String param1 = intent.getStringExtra("finish");

Log.i("mss","intent.getStringExtra(\"finish\") = "+param1);

Intent intent1 = new Intent(ACTION_MSGTEXT);

Log.i("mss","Intent intent1 = new Intent(ACTION_MSGTEXT);");

Log.i("mss",ACTION_MSGTEXT);

intent1.putExtra("msg",param1+",IntentService收到并且广播了出去");

Log.i("mss","intent1.putExtra(\"msg\",param1+\",IntentService收到并且广播了出去\");");

sendBroadcast(intent1);

Log.i("mss","super.sendBroadcast(intent1);");

}

}

}

// /**

// * Handle action Foo in the provided background thread with the provided

// * parameters.

// */

// private void handleActionFoo(String param1, String param2) {

// // TODO: Handle action Foo

// throw new UnsupportedOperationException("Not yet implemented");

// }

// private void handleActionFinish(String param1, String param2) {

// // TODO: Handle action Foo

// throw new UnsupportedOperationException("Not yet implemented");

// }

// /**

// * Handle action Baz in the provided background thread with the provided

// * parameters.

// */

// private void handleActionBaz(String param1, String param2) {

// // TODO: Handle action Baz

// throw new UnsupportedOperationException("Not yet implemented");

// }

}

第三个是AndroidManifest

android:name=".TextIntentService"

android:exported="false">

其中exported="false"的意思是防止其他应用访问该Service