AIDL基本使用3—-in out inout的用

在AIDL中客户端和服务端传入参数 是可以设置流向.仅限参数不包含返回值
1. in :客户端可以传入参数到服务到(默认方法)
2. out:服务端修改客户端传入参数对象 会影响客户端的传入实例
3. inout:服务端即可接受客户端参数也可以修改对其客户端实例影响

这个标签在哪?

这里用AIDL基本使用2的Demo作为案例:AIDL基本使用2

在AIDL基本使用2案例中 IMyAidlInterface.aidl 用来作为客户端和服务端交互的接口.

// IMyAidlInterface.aidl
package com.ucoupon.myservice;
import com.ucoupon.myservice2.Book;interface IMyAidlInterface {String bookIn(in Book mbook);String bookOut(out Book mbook);String bookInout(inout Book mbook);
}

看上面的代码中可以知道.in out inout是用来修饰aidl接口中传入参数.

我们在复习下Book.java 里面有什么

package com.ucoupon.myservice2;import android.os.Parcel;
import android.os.Parcelable;/*** Created by FMY on 2017/5/18.*/public class Book implements Parcelable {String name;int id;public Book(String name, int id) {this.name = name;this.id = id;}protected Book(Parcel in) {name = in.readString();id = in.readInt();}public static final Creator<Book> CREATOR = new Creator<Book>() {@Overridepublic Book createFromParcel(Parcel in) {return new Book(in);}@Overridepublic Book[] newArray(int size) {return new Book[size];}};@Overridepublic int describeContents() {return 0;}@Overridepublic void writeToParcel(Parcel dest, int flags) {dest.writeString(name);dest.writeInt(id);}
}

一个很普通的类有两个字段

• 来编译看看
  编译出错,出错于自动生成接口java文件.new Book()无法被实例化.
  因为根本没有这个构造方法.
  

为什么我们在AIDL基本使用的2中没有报错?
继续查看源码

如果被修饰方法参数为out那么会自动创建修饰参数的空构造方法
在本例中有如下方法被out修饰:
String bookOut(out Book mbook);

解决办法:创建一个空构造方法

• 继续编译
  编译又报错
  

可以看到Book实例化调用readFromParcel方法.可是book没有这个方法.

解决办法:
在Book类中添加此方法.此方法是用于客户端用了out或者inout修饰的方法 中读取服务端修改后的对象的数值在赋值给客户端

package com.ucoupon.myservice2;import android.os.Parcel;
import android.os.Parcelable;/*** Created by FMY on 2017/5/18.*/public class Book implements Parcelable {....public void readFromParcel(Parcel reply) {name = reply.readString();id = reply.readInt();}.....
}

修改后编译通过;

然后把文件拷贝到客户端 进行绑定操作 这一步略过

in测试

来看服务段代码

package com.ucoupon.myservice;import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.IBinder;
import android.os.RemoteException;
import android.support.annotation.Nullable;
import android.util.Log;import com.ucoupon.myservice2.Book;public class MyService extends Service {public MyService() {}@Overridepublic void onCreate() {super.onCreate();Log.d(TAG, "onCreate() called");}//绑定的时候回调@Nullable@Overridepublic IBinder onBind(Intent intent) {Log.d(TAG, "onBind() called with: intent = [" + intent + "]");return new MyAidlInterface();}@Overridepublic int onStartCommand(Intent intent, int flags, int startId) {Log.d(TAG, "onStartCommand() called with: intent = [" + intent + "], flags = [" + flags + "], startId = [" + startId + "]");return super.onStartCommand(intent, flags, startId);}@Overridepublic void unbindService(ServiceConnection conn) {Log.d(TAG, "unbindService() called with: conn = [" + conn + "]");super.unbindService(conn);}@Overridepublic void onRebind(Intent intent) {Log.d(TAG, "onRebind() called with: intent = [" + intent + "]");super.onRebind(intent);}@Overridepublic boolean onUnbind(Intent intent) {Log.d(TAG, "onUnbind() called with: intent = [" + intent + "]");return super.onUnbind(intent);}@Overridepublic void unregisterReceiver(BroadcastReceiver receiver) {Log.d(TAG, "unregisterReceiver() called with: receiver = [" + receiver + "]");super.unregisterReceiver(receiver);}@Overridepublic void onDestroy() {super.onDestroy();Log.d(TAG, "onDestroy() called");}@Overridepublic void onStart(Intent intent, int startId) {Log.d(TAG, "onStart() called with: intent = [" + intent + "], startId = [" + startId + "]");super.onStart(intent, startId);}private static final String TAG = "MyService";class MyAidlInterface extends IMyAidlInterface.Stub{@Overridepublic String bookIn(Book mbook) throws RemoteException {Log.d(TAG, "bookIn() called with: mbook = [" + mbook + "]");mbook.id = 233;return null;}@Overridepublic String bookOut(Book mbook) throws RemoteException {Log.d(TAG, "bookout() called with: mbook = [" + mbook + "]");mbook.id = 233;return null;}@Overridepublic String bookInout(Book mbook) throws RemoteException {Log.d(TAG, "bookInout() called with: mbook = [" + mbook + "]");mbook.id = 233;return null;}}
}

客户端:

package com.ucoupon.aidlstudy;import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;import com.ucoupon.myservice.IMyAidlInterface;
import com.ucoupon.myservice2.Book;public class MainActivity extends AppCompatActivity {private Myconnect myconnect;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//连接管理myconnect = new Myconnect();//意图Intent intent = new Intent();intent.setClassName("com.ucoupon.myservice","com.ucoupon.myservice.MyService");startService(intent);//开始绑定服务bindService(intent,myconnect,BIND_AUTO_CREATE);}private static final String TAG = "MainActivity";class Myconnect implements ServiceConnection {//连接的成功的时候回调@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {Log.d(TAG, "onServiceConnected() called with: name = [" + name + "], service = [" + service + "]");IMyAidlInterface iMyAidlInterface = IMyAidlInterface.Stub.asInterface(service);Book mBook = new Book("客户端", -1);try {Log.e("fmy","客户端没有调用 bookin方法前mBook: name = "+mBook.name+","+" id"+mBook.id);iMyAidlInterface.bookIn(mBook);Log.e("fmy","客户端调用后 bookin方法后mBook: name = "+mBook.name+","+" id"+mBook.id);} catch (RemoteException e) {e.printStackTrace();}//解绑服务
//            unbindService(myconnect);}//断开连接的时候回调@Overridepublic void onServiceDisconnected(ComponentName name) {Log.d(TAG, "onServiceDisconnected() called with: name = [" + name + "]");}}
}

结果预测:
根据前言in 可以让客户端传入一个对象给服务端.但是服务端拿到对象后修改对客户端实例是没有效果

运行结果:
客户端:

E/fmy: 客户端没有调用 bookin方法前mBook: name = 客户端, id-1
客户端调用后 bookin方法后mBook: name = 客户端, id-1

服务端:

 mbook = [Book{name='客户端', id=-1}]

从上面的日志可以发现客户端调用前后book实例是没有任何变化.
服务端也正确读取到客户端发送book实例信息.
回过头来再看看bookIn方法.

  @Overridepublic String bookIn(Book mbook) throws RemoteException {Log.d(TAG, "bookIn() called with: mbook = [" + mbook + "]");mbook.id = 233;return null;}

方法中bookIn对传入的book对象修改了id为233.但是客户端在调用后并有没有影响自身book对象.

out测试

客户端代码和上面in测试差不多,只改变调用bookout方法而已
客户端:

Book mBook = new Book("客户端", -1);try {Log.e("fmy","客户端没有调用 bookout方法前mBook: name = "+mBook.name+","+" id"+mBook.id);iMyAidlInterface.bookOut(mBook);Log.e("fmy","客户端调用后 bookout方法后mBook: name = "+mBook.name+","+" id"+mBook.id);} catch (RemoteException e) {e.printStackTrace();}

预期结果:
out定义:服务端无法读取从客户端传入的参数,但可以改变传入的对象,然后对客户端的实例对象有影响

客户端没有调用 bookout方法前mBook: name = 客户端, id-1
客户端调用后 bookout方法后mBook: name = null, id233

服务端:

mbook = [Book{name='null', id=0}]

判断正确:因为out是客户端无法传入参数给服务端,所以服务端的book参数都为默认值.
这时服务端修改book的id为233.然后把服务端的book传回.所以调用后客户端的name为空 id为233

AIDL基本使用4—-linkToDeath和unlinkToDeath