android app间通讯方式 安卓app之间如何通信

前言：

AIDL：Android Interface Definition Language，翻译过来就是Android接口定义语言。是用于定义服务器和客户端通信接口的一种描述语言，可以拿来生成用于IPC的代码。所以使用AIDL需要一个服务端和客户端
作用：可以在一个进程中获取另一个进程的数据和调用其暴露出来的方法，从而满足进程间通信的需求。

1.AIDL支持的基本数据类型

1. 八种基本数据类型：byte、char、short、int、long、float、double、boolean
2. String，CharSequence
3. 实现了Parcelable接口的数据类型
4. List 类型。List承载的数据必须是AIDL支持的类型，或者是其它声明的AIDL对象
5. Map类型。Map承载的数据必须是AIDL支持的类型，或者是其它声明的AIDL对象

2.服务端的实现

   创建工程，以及所需aidl文件

• 使用Android Studio新建一个工程,命名为TestAidlDemo1
• 右键New一个AIDL文件，取名为IAidlInterface，AS会自动在工程目录生成一个路径完全一样的aidl文件夹
• 既然是要回调消息，那就还需要一个回调接口，同样的方法，创建IAidlCallBack.aidl文件，那么接下来就进行代码编写

实现代码逻辑

• 编写IAidlInterface.aldi代码，因为我们需要回调消息，那么我们需要注册回调以及注销回调接口，一个发送消息的接口，一个获取历史消息的接口，代码如下(AIDL文件不会自动导包,一些不是基本支持数据类型需要我们自己手动import，)

import com.pgc.testaidldemo1.IAidlCallBack;
interface IAidlInterface {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    void registerCallBack(IAidlCallBack iAidlCallBack);
    void unregisterCallBack(IAidlCallBack iAidlCallBack);
    void sendMessage(String message);
    List<String> getMessages();
}

• 编写IAidlCallBack.aidl代码：既然是回调接口，那么我们只需要一个消息发送成功的回调接口就行，代码如下

interface IAidlCallBack {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    void onMessageSuccess(String message);
}

• 既然是服务端，我们需要实现接收消息已经处理消息的逻辑代码，所以我们创建一个AidlService，继承Service,因为Service不能直接接收Callback,但是提供了RemoteCallbackList来注册回调

private RemoteCallbackList<IAidlCallBack> callbackList= new RemoteCallbackList<>();

同时RemoteCallbackList提供了beginBroadcast来获取当前注册的回调数，因此我们可以通过这个方法进行回调处理(再使用了beginBroadcast之后必须调用finishBroadcast不然会报beginBroadcast() called while already in a broadcast错误)

final int num=callbackList.beginBroadcast();
for (int i=0;i<num;i++){
     IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i);
     iAidlCallBack.onMessageSuccess(message);
    }
callbackList.finishBroadcast();

 接下来实例化binder对象并返回给客户端，

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

    private final IAidlInterface.Stub binder=new IAidlInterface.Stub() {
        @Override
        public void registerCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
            callbackList.register(iAidlCallBack);
        }

        @Override
        public void unregisterCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
            callbackList.unregister(iAidlCallBack);
        }

        @Override
        public void sendMessage(String message) throws RemoteException {
            messages.add(message);
            final int num=callbackList.beginBroadcast();
            for (int i=0;i<num;i++){
                IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i);
                iAidlCallBack.onMessageSuccess(message);
            }
            callbackList.finishBroadcast();
        }

        @Override
        public List<String> getMessages() throws RemoteException {
            return messages;
        }
    };

• 在AndroidManifest.xml注册Service

<service android:name=".AidlService"
         android:enabled="true"
         android:exported="true"
            >
    <intent-filter android:priority="1000">
            <action android:name="AIDL.service"></action>
   </intent-filter>
</service>

• AidlService全部代码

package com.pgc.testaidldemo1;

import android.annotation.SuppressLint;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteCallbackList;
import android.os.RemoteException;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.List;


/**
 * Created by PengGuiChu on 2020/4/11.
 */
@SuppressLint("Registered")
public class AidlService extends Service {
    private RemoteCallbackList<IAidlCallBack> callbackList= new RemoteCallbackList<>();
    private List<String> messages=new ArrayList<>();
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    private final IAidlInterface.Stub binder=new IAidlInterface.Stub() {
        @Override
        public void registerCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
            callbackList.register(iAidlCallBack);
        }

        @Override
        public void unregisterCallBack(IAidlCallBack iAidlCallBack) throws RemoteException {
            callbackList.unregister(iAidlCallBack);
        }

        @Override
        public void sendMessage(String message) throws RemoteException {
            messages.add(message);
            final int num=callbackList.beginBroadcast();
            for (int i=0;i<num;i++){
                IAidlCallBack iAidlCallBack=callbackList.getBroadcastItem(i);
                iAidlCallBack.onMessageSuccess(message);
            }
            callbackList.finishBroadcast();
        }

        @Override
        public List<String> getMessages() throws RemoteException {
            return messages;
        }
    };

    @Override
    public void onCreate() {
        super.onCreate();
    }
}

• 因为是服务端和客户端实现相互消息回调，因此在服务端也需要通过binderService来获取binder，相对客户端，因为服务端和AidlService是在同一线程，我们可以直接binderService

Intent intent=new Intent(getApplicationContext(),AidlService.class);
bindService(intent,serviceConnection,BIND_AUTO_CREATE);

然后实例化ServiceConnection

private ServiceConnection serviceConnection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {

        }
};

然后在onServiceConnected中获取binder

iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
try {
      iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);//监听进程是否消失
      iAidlInterface.registerCallBack(iAidlCallBack);//注册消息回调
      messages.addAll(iAidlInterface.getMessages());//获取历史消息
      listView.setAdapter(arrayAdapter=new ArrayAdapter<> 
      (getApplicationContext(),android.R.layout.simple_list_item_1,messages));
} catch (RemoteException e) {
       e.printStackTrace();
}

DeathRecipient实例

private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
        //当承载IBinder的进程消失时接收回调的接口
        @Override
        public void binderDied() {
            if (null == iAidlInterface) {
                return;
            }
            try {
                iAidlInterface.unregisterCallBack(iAidlCallBack);//注销
            } catch (RemoteException e) {
                e.printStackTrace();
            }
            iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
            iAidlInterface = null;
        }
    };

iAidlCallBack实例

private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
        @Override
        public void onMessageSuccess(String message) {
            if (messages!=null&&arrayAdapter!=null){
                messages.add(message);
                handler.sendEmptyMessage(1);
            }
        }
    };

 MainActivity全部代码

package com.pgc.testaidldemo1;



import android.annotation.SuppressLint;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {
    @BindView(R.id.list_view)
    ListView listView;
    private IAidlInterface iAidlInterface;
    private int num;
    private List<String> messages=new ArrayList<>();
    private ArrayAdapter arrayAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        Intent intent=new Intent(getApplicationContext(),AidlService.class);
        bindService(intent,serviceConnection,BIND_AUTO_CREATE);
    }


    @OnClick(R.id.send_message)
    public void onViewClicked(View view) {
        if (iAidlInterface!=null){
            try {
                iAidlInterface.sendMessage("消息"+num);
                num++;
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
    }

    private ServiceConnection serviceConnection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
            try {
                iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);//监听进程是否消失
                iAidlInterface.registerCallBack(iAidlCallBack);//注册消息回调
                messages.addAll(iAidlInterface.getMessages());//获取历史消息
                listView.setAdapter(arrayAdapter=new ArrayAdapter<>(getApplicationContext(),android.R.layout.simple_list_item_1,messages));
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {

        }
    };

    private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
        //当承载IBinder的进程消失时接收回调的接口
        @Override
        public void binderDied() {
            if (null == iAidlInterface) {
                return;
            }
            try {
                iAidlInterface.unregisterCallBack(iAidlCallBack);//注销
            } catch (RemoteException e) {
                e.printStackTrace();
            }
            iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
            iAidlInterface = null;
        }
    };

    private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
        @Override
        public void onMessageSuccess(String message) {
            if (messages!=null&&arrayAdapter!=null){
                messages.add(message);
                handler.sendEmptyMessage(1);
            }
        }
    };

    @SuppressLint("HandlerLeak")
    private Handler handler=new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            arrayAdapter.notifyDataSetChanged();
        }
    };

    @Override
    protected void onDestroy() {
        //解除注册
        if (null != iAidlInterface && iAidlInterface.asBinder().isBinderAlive()) {
            try {
                iAidlInterface.unregisterCallBack(iAidlCallBack);
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        //解除绑定服务
        unbindService(serviceConnection);
        super.onDestroy();
    }
}

到此我们的服务端就编码完成，实现效果

3.客户端实现

   创建client工程

•      选中TestAidlDemo1工程右键NEW一个model，命名为client
• 要想client项目能够连接上Service，我们直接复制上面工程的aidl文件到client工程的main文件里，这样是为了保证两个项目的aidl文件路径一致

       

• 而调用逻辑基本和上面MainActivity一样，需要注意一点的是，因为是两个不同进程，在这里我们不能直接bindService来调起服务端，而是通过以下代码实现

Intent intent=new Intent();
String ACTION = "AIDL.service";//对应服务端AndroidManifest.xml配置service action:name
intent.setAction(ACTION);
intent.setPackage("com.pgc.testaidldemo1");//对应服务端AndroidManifest.xml package
bindService(intent,serviceConnection,BIND_AUTO_CREATE);

• client的MainActivity全部代码

package com.pgc.client;

import android.annotation.SuppressLint;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.pgc.testaidldemo1.IAidlCallBack;
import com.pgc.testaidldemo1.IAidlInterface;

import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {
    @BindView(R.id.list_view)
    ListView listView;
    private IAidlInterface iAidlInterface;
    private int num;
    private List<String> messages=new ArrayList<>();
    private ArrayAdapter arrayAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        Intent intent=new Intent();
        String ACTION = "AIDL.service";
        intent.setAction(ACTION);
        intent.setPackage("com.pgc.testaidldemo1");
        bindService(intent,serviceConnection,BIND_AUTO_CREATE);
    }


    @OnClick(R.id.send_message)
    public void onViewClicked(View view) {
        if (iAidlInterface!=null){
            try {
                iAidlInterface.sendMessage("消息"+num);
                num++;
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
    }

    private ServiceConnection serviceConnection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            iAidlInterface=IAidlInterface.Stub.asInterface(iBinder);
            try {
                iAidlInterface.asBinder().linkToDeath(mDeathRecipient, 0);
                iAidlInterface.registerCallBack(iAidlCallBack);
                messages.addAll(iAidlInterface.getMessages());
                listView.setAdapter(arrayAdapter=new ArrayAdapter<>(getApplicationContext(),android.R.layout.simple_list_item_1,messages));
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {

        }
    };

    private IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
        //当承载IBinder的进程消失时接收回调的接口
        @Override
        public void binderDied() {
            if (null == iAidlInterface) {
                return;
            }
            iAidlInterface.asBinder().unlinkToDeath(mDeathRecipient, 0);
            iAidlInterface = null;
            //断线重来逻辑
        }
    };

    private IAidlCallBack iAidlCallBack=new IAidlCallBack.Stub() {
        @Override
        public void onMessageSuccess(String message) {
            if (messages!=null&&arrayAdapter!=null){
                messages.add(message);
                handler.sendEmptyMessage(1);
            }
        }
    };

    @SuppressLint("HandlerLeak")
    private Handler handler=new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            arrayAdapter.notifyDataSetChanged();
        }
    };

    @Override
    protected void onDestroy() {
        //解除注册
        if (null != iAidlInterface && iAidlInterface.asBinder().isBinderAlive()) {
            try {
                iAidlInterface.unregisterCallBack(iAidlCallBack);
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        //解除绑定服务
        unbindService(serviceConnection);
        super.onDestroy();
    }
}

• 运行效果