Android之service实例

第一步:新建一个Android工程，我这里命名为ServiceDemo.

第二步:修改main.xml代码，我这里增加了四个按钮,代码如下:

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<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    ><TextViewandroid:id="@+id/text"      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/hello"    /><Buttonandroid:id="@+id/startservice"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="startService"/><Buttonandroid:id="@+id/stopservice"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="stopService"/><Buttonandroid:id="@+id/bindservice"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="bindService"/><Buttonandroid:id="@+id/unbindservice"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="unbindService"/></LinearLayout>

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第三步:新建一个Service，命名为MyService.java代码如下:

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package com.tutor.servicedemo;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;import android.text.format.Time;import android.util.Log;public class MyService extends Service {//定义个一个Tag标签private static final String TAG = "MyService";//这里定义吧一个Binder类，用在onBind()有方法里，这样Activity那边可以获取到private MyBinder mBinder = new MyBinder();@Overridepublic IBinder onBind(Intent intent) {Log.e(TAG, "start IBinder~~~");return mBinder;}@Overridepublic void onCreate() {Log.e(TAG, "start onCreate~~~");super.onCreate();}@Overridepublic void onStart(Intent intent, int startId) {Log.e(TAG, "start onStart~~~");super.onStart(intent, startId);}@Overridepublic void onDestroy() {Log.e(TAG, "start onDestroy~~~");super.onDestroy();}@Overridepublic boolean onUnbind(Intent intent) {Log.e(TAG, "start onUnbind~~~");return super.onUnbind(intent);}//这里我写了一个获取当前时间的函数，不过没有格式化就先这么着吧public String getSystemTime(){Time t = new Time();t.setToNow();return t.toString();}public class MyBinder extends Binder{MyService getService(){return MyService.this;}}}

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第四步:修改ServiceDemo.java，代码如下:

package com.tutor.servicedemo;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.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;public class ServiceDemo extends Activity implements OnClickListener{   private MyService  mMyService;private TextView mTextView;private Button startServiceButton;private Button stopServiceButton;private Button bindServiceButton;private Button unbindServiceButton;private Context mContext;//这里需要用到ServiceConnection在Context.bindService和context.unBindService()里用到private ServiceConnection mServiceConnection = new ServiceConnection() {//当我bindService时，让TextView显示MyService里getSystemTime()方法的返回值public void onServiceConnected(ComponentName name, IBinder service) {// TODO Auto-generated method stubmMyService = ((MyService.MyBinder)service).getService();mTextView.setText("I am frome Service :" + mMyService.getSystemTime());}public void onServiceDisconnected(ComponentName name) {// TODO Auto-generated method stub}};    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        setupViews();    }        public void setupViews(){        mContext = ServiceDemo.this;    mTextView = (TextView)findViewById(R.id.text);                startServiceButton = (Button)findViewById(R.id.startservice);    stopServiceButton = (Button)findViewById(R.id.stopservice);    bindServiceButton = (Button)findViewById(R.id.bindservice);    unbindServiceButton = (Button)findViewById(R.id.unbindservice);        startServiceButton.setOnClickListener(this);    stopServiceButton.setOnClickListener(this);    bindServiceButton.setOnClickListener(this);    unbindServiceButton.setOnClickListener(this);    }   public void onClick(View v) {// TODO Auto-generated method stubif(v == startServiceButton){Intent i  = new Intent();i.setClass(ServiceDemo.this, MyService.class);mContext.startService(i);}else if(v == stopServiceButton){Intent i  = new Intent();i.setClass(ServiceDemo.this, MyService.class);mContext.stopService(i);}else if(v == bindServiceButton){Intent i  = new Intent();i.setClass(ServiceDemo.this, MyService.class);mContext.bindService(i, mServiceConnection, BIND_AUTO_CREATE);}else{mContext.unbindService(mServiceConnection);}}}

?第五步:修改AndroidManifest.xml代码(将我们新建的MyService注册进去如下代码第14行:)?

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"      package="com.tutor.servicedemo"      android:versionCode="1"      android:versionName="1.0">    <application android:icon="@drawable/icon" android:label="@string/app_name">        <activity android:name=".ServiceDemo"                  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=".MyService" android:exported="true"></service>    </application>    <uses-sdk android:minSdkVersion="7" /></manifest> 

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第六步:执行上述工程,效果图如下:

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点击startServie按钮时先后执行了Service中onCreate()->onStart()这两个方法，打开Logcat视窗效果如下图:

我们这时可以按HOME键进入Settings(设置)->Applications(应用）->Running Services(正在运行的服务）看一下我们新启动了一个服务，效果如下:

点击stopService按钮时，Service则执行了onDestroy()方法，效果图如下所示:

这时候我们再次点击startService按钮，然后点击bindService按钮(通常bindService都是bind已经启动的Service)，我们看一下Service执行了IBinder()方法，以及TextView的值也有所变化了，如下两张图所示:

最后点击unbindService按钮，则Service执行了onUnbind()方法，如下图所示:

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