【Android】使用AIDL实现进程间通讯简单案例

1 AIDL 简介

​ AIDL（Android Interface Definition Language）是一种接口定义语言，用于生成可在 Android 设备上两个进程之间进行进程间通信（IPC）的代码。通过定义编辑 adil 文件，build 后生成对应的 java 类。

​ 如下，为定义的 MessageManager.aidl 文件经 build 后，生成的 MessageManager.java 接口的框架。该接口包含 sendMsg() 和 getMsg() 两个方法，以及一个名为 Stub 的静态抽象内部类；Stub 继承了 Binder，并实现了 MessageManager 接口，其内部定义了一个名为 Proxy 的静态内部类；Proxy 实现了 MessageManager 接口。

系统生成的 MessageManager 接口框架

​ 服务端：MessageManager.Stub mBind = new MessageManager.Stub()

​ 客户端：mMessageManager = MessageManager.Stub.asInterface(service)（service 是服务端传过来的Binder，即 mBind）

​ 本文全部代码见→使用AIDL实现进程间通讯简单案例

2 项目结构

​ 注意： aidl_C 和 aidl_S 下的 com.zhyan8.aidl 包名及其中的 aidl 文件必须一致。

3 服务端 aidl_S 代码

​ （1）创建 aidl 文件

​ MessageManager.aidl

package com.zhyan8.aidl;

interface MessageManager {
    void sendMsg(String msg);
    String getMsg();
}

​ 注意：方法前不要添加 public 等修饰符。

​ （2）创建服务

​ MyService.java

package com.zhyan8.aidl_s;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import com.zhyan8.aidl.MessageManager;

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        return mBind;
    }

    MessageManager.Stub mBind = new MessageManager.Stub() {
        @Override
        public void sendMsg(String msg) throws RemoteException {
            Log.d("MyService", "客户端发来消息: " + msg);
            System.out.println(msg);
        }

        @Override
        public String getMsg() throws RemoteException {
            return "abcde"; //客户端待接收的消息
        }
    };
}

​ （3）注册服务

​ 在 AndroidManifest.xml 文件中 application 节点下注册 service，如下。

<service
    android:name=".MyService"
    android:enabled="true"
    android:exported="true">
    <intent-filter>
        <action android:name="com.xxx.aidl"/>
    </intent-filter>
</service>

​ （4）主 Activity

​ MainActivity.java

package com.zhyan8.aidl_s;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

4 客户端 aidl_C 代码

​ （1）复制 aidl 文件

​ 将 aidl_S 下的 com.zhyan8.aidl 包及其中的 aidl 文件复制到 aidl_C 中 。

​ （2）设计布局

​ activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.zhyan8.aidl_c.MainActivity">

    <EditText
        android:id="@+id/et_msg"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:textSize="30sp"
        android:background="#ffcc66"/>

    <Button
        android:id="@+id/btn_send"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:text="发送"
        android:textSize="30sp"
        android:layout_marginTop="30dp"/>

    <TextView
        android:id="@+id/tv_msg"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:textSize="30sp"
        android:background="#ffcc66"
        android:layout_marginTop="50dp"/>

    <Button
        android:id="@+id/btn_recv"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:text="接收"
        android:textSize="30sp"
        android:layout_marginTop="30dp"/>
</LinearLayout>

​ 界面如下：

​ （3）主 Activity

​ MainActivity.java

package com.zhyan8.aidl_c;

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.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.zhyan8.aidl.MessageManager;

public class MainActivity extends AppCompatActivity {
    private MessageManager mMessageManager;
    private EditText et_msg;
    private Button btn_send;
    private TextView tv_msg;
    private Button btn_recv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
    }

    public void init() {
        et_msg = (EditText) findViewById(R.id.et_msg);
        btn_send = (Button) findViewById(R.id.btn_send);
        tv_msg = (TextView) findViewById(R.id.tv_msg);
        btn_recv = (Button) findViewById(R.id.btn_recv);
        btn_send.setOnClickListener(cl);
        btn_recv.setOnClickListener(cl);
    }

    View.OnClickListener cl = new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            if (v.getId()==R.id.btn_send) {
                String str = et_msg.getText().toString();
                sendMsg(str);
            }else if(v.getId()==R.id.btn_recv) {
                String str = getMsg();
                tv_msg.setText(str);
            }
        }
    };

    private void sendMsg(String str){
        if (mMessageManager==null) {
            attemptToBindService();
        }
        try {
            mMessageManager.sendMsg(str);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    private String getMsg(){
        if (mMessageManager==null) {
            attemptToBindService();
        }
        try {
            String str = mMessageManager.getMsg();
            return str;
        } catch (RemoteException e) {
            e.printStackTrace();
        }
        return "";
    }

    private void attemptToBindService() {
        Intent intent = new Intent();
        intent.setAction("com.xxx.aidl");
        intent.setPackage("com.zhyan8.aidl_s");
        bindService(intent, conn, Context.BIND_AUTO_CREATE);
    }

    ServiceConnection conn = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            mMessageManager = MessageManager.Stub.asInterface(service);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            mMessageManager = null;
        }
    };

    @Override
    protected void onStart() {
        super.onStart();
        if (mMessageManager==null) {
            attemptToBindService();
        }
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (mMessageManager!=null) {
            unbindService(conn);
        }
    }
}

​ 注意：intent.setPackage("com.zhyan8.aidl_s") 中的 "com.zhyan8.aidl_s" 应与服务端 aidl_S 的 build.gradle 中 applicationId 属性的值一致，如下：

5 效果展示

​ （1）发送消息

​ 在 EditView 中输入【Qwert】，点击【发送】按钮，在服务端可以收到发送的消息，如下：

​ （2）接收消息

​ 点击【接收】按钮，客户端 aidl_C 界面可以看到服务端 aidl_S 传过来的字符串【abcde】，如下：

6 附件

​ 以下是点击【Make Build】后自动生成的代码，路径为【aild_C\build\generated\source\aidl\debug\commu\ 】

​ MessageManager.java

package com.zhyan8.aidl;

public interface MessageManager extends android.os.IInterface {

    public static class Default implements com.zhyan8.aidl.MessageManager {
        @Override
        public void sendMsg(java.lang.String msg) throws android.os.RemoteException {
        }

        @Override
        public java.lang.String getMsg() throws android.os.RemoteException {
            return null;
        }

        @Override
        public android.os.IBinder asBinder() {
            return null;
        }
    }

    public static abstract class Stub extends android.os.Binder implements com.zhyan8.aidl.MessageManager {
        private static final java.lang.String DESCRIPTOR = "com.zhyan8.aidl.MessageManager";

        public Stub() {
            this.attachInterface(this, DESCRIPTOR);
        }

        public static com.zhyan8.aidl.MessageManager asInterface(android.os.IBinder obj) {
            if ((obj == null)) {
                return null;
            }
            android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
            if (((iin != null) && (iin instanceof com.zhyan8.aidl.MessageManager))) {
                return ((com.zhyan8.aidl.MessageManager) iin);
            }
            return new com.zhyan8.aidl.MessageManager.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 {
            java.lang.String descriptor = DESCRIPTOR;
            switch (code) {
                case INTERFACE_TRANSACTION: {
                    reply.writeString(descriptor);
                    return true;
                }
                case TRANSACTION_sendMsg: {
                    data.enforceInterface(descriptor);
                    java.lang.String _arg0;
                    _arg0 = data.readString();
                    this.sendMsg(_arg0);
                    reply.writeNoException();
                    return true;
                }
                case TRANSACTION_getMsg: {
                    data.enforceInterface(descriptor);
                    java.lang.String _result = this.getMsg();
                    reply.writeNoException();
                    reply.writeString(_result);
                    return true;
                }
                default: {
                    return super.onTransact(code, data, reply, flags);
                }
            }
        }

        private static class Proxy implements com.zhyan8.aidl.MessageManager {
            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 void sendMsg(java.lang.String msg) throws android.os.RemoteException {
                android.os.Parcel _data = android.os.Parcel.obtain();
                android.os.Parcel _reply = android.os.Parcel.obtain();
                try {
                    _data.writeInterfaceToken(DESCRIPTOR);
                    _data.writeString(msg);
                    boolean _status = mRemote.transact(Stub.TRANSACTION_sendMsg, _data, _reply, 0);
                    if (!_status && getDefaultImpl() != null) {
                        getDefaultImpl().sendMsg(msg);
                        return;
                    }
                    _reply.readException();
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
            }

            @Override
            public java.lang.String getMsg() 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);
                    boolean _status = mRemote.transact(Stub.TRANSACTION_getMsg, _data, _reply, 0);
                    if (!_status && getDefaultImpl() != null) {
                        return getDefaultImpl().getMsg();
                    }
                    _reply.readException();
                    _result = _reply.readString();
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
                return _result;
            }

            public static com.zhyan8.aidl.MessageManager sDefaultImpl;
        }

        static final int TRANSACTION_sendMsg = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
        static final int TRANSACTION_getMsg = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);

        public static boolean setDefaultImpl(com.zhyan8.aidl.MessageManager impl) {
            if (Stub.Proxy.sDefaultImpl == null && impl != null) {
                Stub.Proxy.sDefaultImpl = impl;
                return true;
            }
            return false;
        }

        public static com.zhyan8.aidl.MessageManager getDefaultImpl() {
            return Stub.Proxy.sDefaultImpl;
        }
    }

    public void sendMsg(java.lang.String msg) throws android.os.RemoteException;

    public java.lang.String getMsg() throws android.os.RemoteException;
}

​ 声明：本文转自【Android】使用AIDL实现进程间通讯简单案例