.Net程序员玩转Android开发---(19)Android IntentService服务

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Intentservice服务也是安卓中的一个服务，它继承与service,但与servcie有所不同，它新开启一个线程来处理所有的请求，不需要再UI等待处理，onStartCommand方法把所有请求发送到工作队列中，，然后再由工作队列发送到onHandlerIntent中进行处理

1.interservice默认情况下是新开启一个线程来处理任务, service默认是在ui线程执行

2. interservice会创建一个工作队列来处理接受到任务，只用当前任务处理完成，才能处理下一个任务，否则下一个任务一直处于等待状态.

3.所有的请求任务处理完成后，系统会自动停止服务，不需要手动停止stopselft

下面的例子展示intentservice不断接受外部传了的消息，并按顺序处理，首先在onStartCommand里面接受消息存入队列，然后在onHandleIntent进行处理

1.创建intentservice服务

package com.example.helloword;import android.app.IntentService;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.util.Log;import android.widget.Toast;public class ReceiveIntentService extends IntentService  {String receivemsg;private Handler handler = new Handler() {         public void handleMessage(android.os.Message msg) {             Toast.makeText(ReceiveIntentService.this, " 接受消息:" + receivemsg, Toast.LENGTH_LONG).show();         }      };  public ReceiveIntentService() {super("1111");// TODO Auto-generated constructor stub}public ReceiveIntentService(String name) {super(name);// TODO Auto-generated constructor stub}@Override     public int onStartCommand(Intent intent, int flags, int startId) {  Bundle bundle = intent.getExtras();  receivemsg= bundle.getString("para");       return super.onStartCommand(intent, flags, startId);     }  @Overrideprotected void onHandleIntent(Intent intent) {// TODO Auto-generated method stub  try {Thread.sleep(5000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}  handler.sendEmptyMessage(0);  }}

2.通过activity不断向intentservice发送消息

布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <EditText        android:id="@+id/etpostmsg"        android:layout_width="275dp"        android:layout_height="wrap_content" >            </EditText>        <Button        android:id="@+id/btnpostmsg"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="发送请求" /></LinearLayout>

后台IntentActivity

package com.example.helloword;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class IntentActivity extends Activity {private Button btnpost;//启动服务private EditText etmsg;Intent intent;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.intentlayout);btnpost=(Button)findViewById(R.id.btnpostmsg);etmsg=(EditText)findViewById(R.id.etpostmsg);btnpost.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stub intent = new Intent("com.example.helloword.ReceiveIntentService");  Bundle bundle = new Bundle();   bundle.putString("para",etmsg.getText().toString());    intent.putExtras(bundle);           startService(intent);      }});}}

AndroidManifest.xml添加配置

                  <activity android:name="com.example.helloword.IntentActivity">             <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>          <service   android:name=".ReceiveIntentService">     <intent-filter>          <action android:name="com.example.helloword.ReceiveIntentService" />          <category android:name="android.intent.category.default" />    </intent-filter>  </service>

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