android service总结

1、通过startservice方法启动一个服务，service不能自己启动自己。若在一个服务中启动一个activity则，必须是申明一个全新的activity任务TASK。通过startservice方法启动的服务不会随着启动组件的消亡而消亡，而是一直运行着。

Service生命周期 onCreate()-------->onStartCommand()----------->onDestroy() 

startService()启动一个服务后，若在该服务做耗时操作且没有写线程，则会导致主线程阻塞！

服务启动运行后会一直运行onStartCommand()方法。

2、用bindService启动一个服务，该服务和activity是绑定在一起的：启动时，先调用onCreate()------>onBind()--------->onServiceConnected()，启动服务的组件消亡，服务也就消亡了。

3、AIDL服务调用方式

demo下载地址:http://download.csdn.net/detail/u014600432/8175529

1)服务端代码:

首先定义一个接口描述语言的接口：

package com.example.service;interface DataService{double getData(String arg);}

然后定义服务组件代码：

/** *Version: *author:YangQuanqing *Data: */package com.example.android_aidl_service;import com.example.service.DataService;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;import android.os.RemoteException;/** * @author YangQuanqing yqq * */public class MyService extends Service {@Overridepublic IBinder onBind(Intent arg0) {<span style="color:#ff0000;">//返回binder由didl文件生成</span>return binder;}//定义给客户端调用的方法 (aidl文件)Binder binder=new <span style="color:#ff0000;">DataService.Stub()</span> {@Overridepublic double getData(String arg) throws RemoteException {if(arg=="a"){return 1;}if(arg=="b"){return 2;}return 0;}};}

服务端的清单文件：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.android_aidl_service"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.android_aidl_service.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>        <service             android:name="com.example.android_aidl_service.MyService"            >            <intent-filter>                <!-- 意图过滤器要把aidl包名加类名 -->                <action android:name="com.example.service.DataService"/>            </intent-filter>        </service>    </application></manifest>

客户端编码：

把aidl文件包拷贝到客户端，客户端代码如下：

package com.example.android_aidl_client;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.os.RemoteException;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import com.example.service.DataService;public class MainActivity extends Activity {private Button btn1,btn2;//定义一个AIDL实例private DataService dataService;private TextView tv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btn1=(Button)this.findViewById(R.id.button1);btn2=(Button)this.findViewById(R.id.button2);tv=(TextView)this.findViewById(R.id.textView1);//绑定服务btn1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent=new Intent(DataService.class.getName());//启动服务bindService(intent, conn, BIND_AUTO_CREATE);}});//调用服务的方法btn2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {try {int result=(int) dataService.getData("a");tv.setText(result+"");} catch (RemoteException e) {// TODO Auto-generated catch blocke.printStackTrace();}}});}//客户端与服务交互private ServiceConnection conn=new ServiceConnection() {@Overridepublic void onServiceDisconnected(ComponentName name) {}@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {//传入servicedataService=DataService.Stub.asInterface(service);}};@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

这样就可以完成进程间通信了。

4、用bindService启动服务并访问本地服务的方法。

访问界面代码：

package com.example.android_service_binder;import android.app.Activity;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.content.ServiceConnection;import android.os.Bundle;import android.os.IBinder;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import com.example.android_service_binder.MyService.LocalBinder;public class MainActivity extends Activity {//销毁绑定@Overrideprotected void onStop() {super.onStop();if(flag){//解除绑定unbindService(serviceConnection);flag=false;}}//绑定Service@Overrideprotected void onStart() {// TODO Auto-generated method stubsuper.onStart();/*Intent intent=new Intent(MainActivity.this,MyService.class);//启动servicebindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);*/}private Button btnBinder=null;private Button btnCall=null;private TextView tv=null;private MyService myService;//service实例private boolean flag=false;//默认不绑定@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btnBinder=(Button)this.findViewById(R.id.button1);btnCall=(Button)this.findViewById(R.id.button2);tv=(TextView)this.findViewById(R.id.textView1);btnBinder.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent=new Intent(MainActivity.this,MyService.class);//启动servicebindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);}});//调用service方法btnCall.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {//处于绑定状态if(flag){int result=myService.getRandom();tv.setText("<<<<<"+result);}}});}private ServiceConnection serviceConnection= new ServiceConnection(){//连接@Overridepublic void onServiceConnected(ComponentName arg0, IBinder iBinder) {//获得服务的The IBinder of the Service's communication channel, which you can now make calls on.LocalBinder binder=(LocalBinder) iBinder;//获得服务myService=binder.getService();flag=true;}//不连接@Overridepublic void onServiceDisconnected(ComponentName arg0) {flag=false;}};@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

服务组件代码：

/** *Version: *author:YangQuanqing *Data: */package com.example.android_service_binder;import java.util.Random;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;/** * @author YangQuanqing yqq * */public class MyService extends Service {private final LocalBinder lb=new LocalBinder();private final Random num=new Random();@Overridepublic IBinder onBind(Intent arg0) {// 返回本地Binder的子类实例return  lb;}//定义一个本地Binder类继承Binderpublic class LocalBinder extends Binder{//获得Servie子类当前实例给客户端public MyService getService(){return MyService.this;}}public int getRandom(){return num.nextInt(98);}}

通过该demo可以访问本地服务里面的方法。

demo下载地址：http://download.csdn.net/detail/u014600432/8175633

5、IntentService

本质是开启一个线程来完成耗时操作。

IntentService生命周期:

onCreate()------->onStartCommand()--------->onHandleIntent()--------->onDestroy()

/** *Version: *author:YangQuanqing *Data: */package com.example.android_intentservice;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.util.EntityUtils;import android.app.IntentService;import android.content.Intent;import android.os.Environment;import android.widget.Toast;/** * @author YangQuanqing  不需要开启线程(看源码知道是自己封装了开启线程)，不需要关闭服务，自己关闭,单线程下载数据 *  * 一定要记得实例化！！！ */public class DownLoadService extends IntentService {@Overridepublic void onCreate() {// TODO Auto-generated method stubsuper.onCreate();}public DownLoadService() {super("DownLoadService");}// 只需复写如下方法// 在该方法中执行操作@Overrideprotected void onHandleIntent(Intent intent) {// 获得提取网络资源的实例HttpClient httpClient = new DefaultHttpClient();// 设置请求方式HttpPost httpPost = new HttpPost(intent.getStringExtra("url"));// 设置存储路径File file = new File(Environment.getExternalStorageDirectory(),"IntentService.gif");// 定义输出流用于写FileOutputStream fileOutputStream = null;byte[] data = null;// 网络数据try {// 执行请求获得响应HttpResponse httpResponse = httpClient.execute(httpPost);// 判断响应状态码if (httpResponse.getStatusLine().getStatusCode() == 200) {// 获得响应实体HttpEntity httpEntity = httpResponse.getEntity();// 获得网络数据data = EntityUtils.toByteArray(httpEntity);// 判断SD卡是否可用if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {// 写入SD卡fileOutputStream=new FileOutputStream(file);fileOutputStream.write(data, 0, data.length);//Toast.makeText( DownLoadService.this,"下载完成", Toast.LENGTH_LONG).show();Toast.makeText( getApplicationContext(),"下载完成", Toast.LENGTH_LONG).show();}}} catch (ClientProtocolException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();} finally {if (fileOutputStream != null) {try {fileOutputStream.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}}

调用服务界面：

package com.example.android_intentservice;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity {private Button btn_intent=null;private String url="http://www.baidu.com/img/bdlogo.gif";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btn_intent=(Button)this.findViewById(R.id.button1);btn_intent.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0) {Intent intent=new Intent(MainActivity.this,DownLoadService.class);intent.putExtra("url", url);startService(intent);}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

demo下载地址：http://download.csdn.net/detail/u014600432/8175673