Android Service详解（二）第一个Service

2024-12-19 技术教程

Service中有四个重要函数：

publicIBinderonBind(Intentarg0)；//必须实现，返回接口给ServicepublicvoidonCreate()；//Service创建时调用publicvoidonStart(Intentintent,intstartId)；//通过startService（）会调用publicvoidonDestroy()；//销毁时StopService()调用

通过StartActivity（）函数启动Service，当第一次调用时会分别调用onCreate()和onStart在()；

之后只会调用onStart()；

通过函数StopService()结束Service，会调用onDestroy()；

调用BindService()：当Service未创建时调用onCreate()和onBind()；当创建了只调用onBind()；

使用函数bindService()和函数unbindService()可以绑定和解除绑定

对已经绑定的Service调用bindService()无效，即多次调用bindService()和调用一次bindService()一样。 unbindService()只能使用一次，即对于一个绑定的Service，只能调用一次unbindService()，多次调用会产生错误

该函数原型为：

bindService(Intent,ServiceConnection,BIND_AUTO_CREATE);

ServiceConnection是一个服务连接类，必须实现以下两个函数：

publicvoidonServiceConnected(ComponentNamearg0,IBinderarg1)//连接成功时调用publicvoidonServiceDisconnected(ComponentNamearg0)//连接失败时调用

示例如下：

privateServiceConnectionconn=newServiceConnection(){@OverridepublicvoidonServiceConnected(ComponentNamearg0,IBinderarg1){//TODOAuto-generatedmethodstubToast.makeText(MainActivity.this,"success",Toast.LENGTH_LONG).show();Log.i("SERVICE","success");}@OverridepublicvoidonServiceDisconnected(ComponentNamearg0){//TODOAuto-generatedmethodstubToast.makeText(MainActivity.this,"errer",Toast.LENGTH_LONG);Log.i("SERVICE","errer");}

Service实例：

MainActivity.java:

protectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Buttonbutton1=(Button)this.findViewById(R.id.btn1);Buttonbutton2=(Button)this.findViewById(R.id.btn3);Buttonbutton3=(Button)this.findViewById(R.id.btn4);Buttonbutton4=(Button)this.findViewById(R.id.btn5);button1.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewarg0){//TODOAuto-generatedmethodstubstartService(newIntent(MainActivity.this,NewService.class));}});button2.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewarg0){//TODOAuto-generatedmethodstubstopService(newIntent(MainActivity.this,NewService.class));}});button3.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewarg0){//TODOAuto-generatedmethodstubbindService(newIntent(MainActivity.this,NewService.class),conn,BIND_AUTO_CREATE);}});button4.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewarg0){//TODOAuto-generatedmethodstubunbindService(conn);}});｝

NewService.java:

publicclassNewServiceextendsService{@OverridepublicIBinderonBind(Intentarg0){//TODOAuto-generatedmethodstubToast.makeText(NewService.this,"onBind",Toast.LENGTH_LONG).show();Log.i("SERVICE","onbind");returnnull;}publicvoidonCreate(){super.onCreate();Log.i("SERVICE","oncreat");Toast.makeText(NewService.this,"onCreat",Toast.LENGTH_LONG).show();}publicvoidonStart(Intentintent,intstartId){Log.i("SERVICE","onstart");Toast.makeText(NewService.this,"onStart",Toast.LENGTH_LONG).show();}publicvoidonDestroy(){Log.i("SERVICE","ondestory");Toast.makeText(NewService.this,"onDestory",Toast.LENGTH_LONG).show();}}

Activity.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical"><Buttonandroid:id="@+id/btn1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="start"/><Buttonandroid:id="@+id/btn3"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="stop"/><Buttonandroid:id="@+id/btn4"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="bind"/><Buttonandroid:id="@+id/btn5"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="unbind"/></LinearLayout>

AndroidManifest.xml增加：

<serviceandroid:name="com.example.new1.NewService"/>