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 {
@Override
public 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> {
@Override
public 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;
@Override
protected 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() {
@Override
public 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() {
@Override
public void onClick(View v) {
try {
int result=(int) dataService.getData("a");
tv.setText(result+"");
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
//客户端与服务交互
private ServiceConnection conn=new ServiceConnection() {
@Override
public void onServiceDisconnected(ComponentName name) {
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
//传入service
dataService=DataService.Stub.asInterface(service);
}
};
@Override
public 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。
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
@Override
protected void onStop() {
super.onStop();
if(flag)
{
//解除绑定
unbindService(serviceConnection);
flag=false;
}
}
//绑定Service
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
/*Intent intent=new Intent(MainActivity.this,MyService.class);
//启动service
bindService(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
@Override
protected 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() {
@Override
public void onClick(View v) {
Intent intent=new Intent(MainActivity.this,MyService.class);
//启动service
bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
}
});
//调用service方法
btnCall.setOnClickListener(new OnClickListener() {
@Override
public 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
@Override
public 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
@Override
public void onServiceDisconnected(ComponentName arg0) {
flag=false;
}
};
@Override
public 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();
@Override
public 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Binder
public 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 {
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
}
public DownLoadService() {
super("DownLoadService");
}
// 只需复写如下方法
// 在该方法中执行操作
@Override
protected 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 block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.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";
@Override
protected 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(){
@Override
public void onClick(View arg0) {
Intent intent=new Intent(MainActivity.this,DownLoadService.class);
intent.putExtra("url", url);
startService(intent);
}
});
}
@Override
public 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