Service个人笔记2（aidl）

      这篇博文讲的是绑定远程服务（aidl）

远程服务与本地服务的区别

远程服务调用可以跨进程调用，通俗的说就是A应用可以调用B应用的服务（前提：已经实现了远程调用的规则）

实现远程服务的思想可以这样理解

我们接下来看一下具体代码是如何实现的

-------------------------------------------------------------------------------------------------首先提供B应用（远程服务提供者）的代码-------------------------------------------------------------------------------------------------

该应用的主要部分

AlipayService.java

IService.aidl

IService.java     (这个是IService.aidl 建立以后adt自动生成的)

（activity没有什么关键内容就不贴代码了）

AlipayService.java

package com.itheima.alipayservice;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.os.RemoteException;import android.widget.Toast;public class AliPayService extends Service {@Overridepublic IBinder onBind(Intent intent) {Toast.makeText(getApplicationContext(), "支付宝服务已绑定", 0).show();return new MyIBinder();}@Overridepublic boolean onUnbind(Intent intent) {Toast.makeText(getApplicationContext(), "支付宝服务已解绑", 0).show();return super.onUnbind(intent);}@Overridepublic void onCreate() {Toast.makeText(getApplicationContext(), "支付宝服务已创建", 0).show();super.onCreate();}@Overridepublic void onDestroy() {Toast.makeText(getApplicationContext(), "支付宝服务已销毁", 0).show();super.onDestroy();}private String pay() {return "支付宝服务提供远程支付服务";}// 这个地方与绑定本地服务有所区别，因为你建立了aidl文件，必须统一规则。// 所以自定义的MyIBinder必须实现 自动生成的IService.java中的内部类private class MyIBinder extends IService.Stub {// Stub 已经 extends Binder 实现了IService接口// public static abstract class Stub extends android.os.Binder// implements com.itheima.alipayservice.IService@Overridepublic String callPay() throws RemoteException {String result = pay();return result;}}}

IService.aidl

package com.itheima.alipayservice;interface IService{String callPay();}

IService.java

/* * This file is auto-generated.  DO NOT MODIFY. * Original file: E:\\java\\Documents and Settings\\margi\\workspace\\42_itheima_alipayservice\\src\\com\\itheima\\alipayservice\\IService.aidl */package com.itheima.alipayservice;public interface IService extends android.os.IInterface{/** Local-side IPC implementation stub class. */public static abstract class Stub extends android.os.Binder implements com.itheima.alipayservice.IService{private static final java.lang.String DESCRIPTOR = "com.itheima.alipayservice.IService";/** Construct the stub at attach it to the interface. */public Stub(){this.attachInterface(this, DESCRIPTOR);}/** * Cast an IBinder object into an com.itheima.alipayservice.IService interface, * generating a proxy if needed. */public static com.itheima.alipayservice.IService asInterface(android.os.IBinder obj){if ((obj==null)) {return null;}android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);if (((iin!=null)&&(iin instanceof com.itheima.alipayservice.IService))) {return ((com.itheima.alipayservice.IService)iin);}return new com.itheima.alipayservice.IService.Stub.Proxy(obj);}@Override public android.os.IBinder asBinder(){return this;}@Override public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException{switch (code){case INTERFACE_TRANSACTION:{reply.writeString(DESCRIPTOR);return true;}case TRANSACTION_callPay:{data.enforceInterface(DESCRIPTOR);java.lang.String _result = this.callPay();reply.writeNoException();reply.writeString(_result);return true;}}return super.onTransact(code, data, reply, flags);}private static class Proxy implements com.itheima.alipayservice.IService{private android.os.IBinder mRemote;Proxy(android.os.IBinder remote){mRemote = remote;}@Override public android.os.IBinder asBinder(){return mRemote;}public java.lang.String getInterfaceDescriptor(){return DESCRIPTOR;}@Override public java.lang.String callPay() throws android.os.RemoteException{android.os.Parcel _data = android.os.Parcel.obtain();android.os.Parcel _reply = android.os.Parcel.obtain();java.lang.String _result;try {_data.writeInterfaceToken(DESCRIPTOR);mRemote.transact(Stub.TRANSACTION_callPay, _data, _reply, 0);_reply.readException();_result = _reply.readString();}finally {_reply.recycle();_data.recycle();}return _result;}}static final int TRANSACTION_callPay = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);}public java.lang.String callPay() throws android.os.RemoteException;}

------------------------------------------------------------------------------------------A应用（远程服务的调用者）-------------------------------------------------------------------------

MainActivity.java

package com.itheima.alipayuser;import com.itheima.alipayservice.IService;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.os.RemoteException;import android.view.View;import android.widget.Toast;public class MainActivity extends Activity {private Intent intent;private IService iService;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);intent = new Intent();intent.setAction("com.itheima.alipay");}public void bind(View view) {this.bindService(intent, new MyConn(), Context.BIND_AUTO_CREATE);}//调用远程服务public void call(View view) {try {    //执行远程服务中的方法String result = this.iService.callPay();Toast.makeText(getApplicationContext(), result, 0).show();} catch (RemoteException e) {//调用远程服务的方法时会抛出remoteexceptione.printStackTrace();}}private class MyConn implements ServiceConnection {@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {//得到远程服务iService = IService.Stub.asInterface(service);//用其自己的方法实现类型转换}@Overridepublic void onServiceDisconnected(ComponentName name) {// TODO Auto-generated method stub}}}

IService.aidl

内容是一样的就不贴代码了

IService.java

必须要注意的是，A应用中（服务调用者）包含 .aidl 文件的package必须和 B应用（服务提供者）保持一致，最好直接复制

最后可以说一下，就是创建  .aidl 文件的时候的步骤

这个步骤你首先可以把它当成一个绑定本地的服务来写，还是把IService定义成一个接口，写成IService.java 然后修改文件后缀名  IService.aidl

最后根据aidl的语法 修改其中的内容。这样思路可能更清晰一些。