Android开发之Service
Android开发之Service
1.创建、配置Service
package com.wwj; import android.app.Service; import android.content.Intent; import android.os.IBinder; public class FirstService extends Service{ //必须实现的方法 @Override public IBinder onBind(Intent intent) { // TODO Auto-generated method stub return null; } // Service被创建时回调该方法 @Override public void onCreate() { // TODO Auto-generated method stub super.onCreate(); System.out.println("Service is Created"); } // Service被启动时回调该方法 @Override public void onStart(Intent intent, int startId) { // TODO Auto-generated method stub super.onStart(intent, startId); System.out.println("Service is started"); } // Service被关闭之前回调 @Override public void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); System.out.println("Service is Destroyed"); } }
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.wwj" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="4" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".ServiceActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <!-- 配置一个Service组件 --> <service android:name=".FirstService"> <intent-filter > <!-- 为该Service组件的intent-filter配置action --> <action android:name="com.wwj.FIRST_SERVICE"/> </intent-filter> </service> </application>
2.启动和停止Service
package com.wwj; 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; public class ServiceActivity extends Activity { /** Called when the activity is first created. */ private Button start,stop; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //获取程序界面中的start、stop两个按钮 start = (Button) findViewById(R.id.start); stop = (Button) findViewById(R.id.stop); //创建启动Service的Intent final Intent intent = new Intent(); //为Intent设置Action属性 intent.setAction("com.wwj.FIRST_SERVICE"); start.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //启动指定Service startService(intent); } }); stop.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //停止指定Service stopService(intent); } }); } }
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:gravity="center_horizontal"> <Button android:id="@+id/start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="启动Service"/> <Button android:id="@+id/stop" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="关闭Service" /> </LinearLayout>
以上为项目:Service的代码
项目运行效果如下:
DDMS的Logcat面板会显示如下信息:
3.绑定本地Service并与之通信
创建项目:BindService
代码如下:
==>BindService.java
package com.wwj; import android.app.Service; import android.content.Intent; import android.content.res.Configuration; import android.os.Binder; import android.os.IBinder; public class BindService extends Service{ private int count; private boolean quit; //定义onBinder方法所返回的对象 private MyBinder binder = new MyBinder(); //通过继承Binder来实现IBinder类 public class MyBinder extends Binder{ public int getCount(){ //获取Service的运行状态:count return count; } } //必须实现的方法 @Override public IBinder onBind(Intent intent) { // TODO Auto-generated method stub System.out.println("Service is Binded "); //返回IBinder对象 return binder; } //Service被创建时回调该方法 @Override public void onCreate() { // TODO Auto-generated method stub super.onCreate(); System.out.println("Service is Created"); //启动一条线程、动态地修改count状态值 new Thread(){ public void run() { while(!quit){ try{ Thread.sleep(1000); }catch(InterruptedException e){ } count++; } }; }.start(); } //Service被断开连接时回调该方法 @Override public boolean onUnbind(Intent intent) { // TODO Auto-generated method stub System.out.println("Service is Unbinded"); return true; } //Service被关闭之前回调 @Override public void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); this.quit = true; System.out.println("Service is Destroyed"); } }
==>BindServiceActivity.java
package com.wwj; import android.app.Activity; import android.app.Service; import android.content.ComponentName; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.IBinder; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Toast; public class BindServiceActivity extends Activity { /** Called when the activity is first created. */ private Button bind, unbind, getServiceStatus; // 保持所启动的Service的IBinder对象 BindService.MyBinder binder; // 定义一个ServiceConnection对象 private ServiceConnection conn = new ServiceConnection() { // 当该Activity与Service断开连接时回调该方法 @Override public void onServiceDisconnected(ComponentName name) { // TODO Auto-generated method stub System.out.println("--Service Disconnected--"); //获取Service的onBind方法返回的MyBinder对象 } // 当该Activity与Service连接成功后回调该方法 @Override public void onServiceConnected(ComponentName name, IBinder service) { // TODO Auto-generated method stub System.out.println("--Service Connected--"); binder = (BindService.MyBinder) service; } }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 获取程序界面中的bind,unbind,getServiceStatus按钮 bind = (Button)findViewById(R.id.bind); unbind = (Button)findViewById(R.id.unbind); getServiceStatus = (Button) findViewById(R.id.getServiceStatus); //创建启动Service的Intent final Intent intent = new Intent(); //为Intent设置Action intent.setAction("com.wwj.BIND_SERVICE"); bind.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //绑定指定Service bindService(intent, conn, Service.BIND_AUTO_CREATE); } }); unbind.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //解除绑定Service unbindService(conn); } }); getServiceStatus.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //获取并显示Service的count值 Toast.makeText(BindServiceActivity.this, "Service的count值为: " + binder.getCount(), 4000).show(); } }); } }
布局文件:main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="horizontal" > <Button android:id="@+id/bind" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="绑定Service" /> <Button android:id="@+id/unbind" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="解除绑定" /> <Button android:id="@+id/getServiceStatus" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="获取Service状态" /> </LinearLayout>
注册文件:
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.wwj" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="4" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".BindServiceActivity" 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=".BindService"> <intent-filter > <action android:name="com.wwj.BIND_SERVICE"/> </intent-filter> </service> </application> </manifest>
项目运行效果: