android ipc跨进程通讯

aidi跨进程通讯在android系统中使用广泛，包括client端和server端。今天写个简单例子记录下：

新建android工程：AIDL_Service（服务端）

选择Android为工程目录视图，在包名上右键新建aidl file，最后会在app/src/main目录下面

package reacheng.com.aidl_service;

// Declare any non-default types here with import statements

interface IMyAidlInterface {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    int AIDL_ADD(in int a,in int b);
}

新建好了之后编译工程

新建服务端的service

public class MyService extends Service {
    @Override
    public void onCreate() {
        super.onCreate();
        android.util.Log.e("MyService","onCreate");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        android.util.Log.e("MyService","onStartCommand");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        android.util.Log.e("MyService","onBind");
        return mBinder;
    }

    @Override
    public void onDestroy() {
        android.util.Log.e("MyService","onDestroy");
        super.onDestroy();
    }

    @Override
    public boolean onUnbind(Intent intent) {
        android.util.Log.e("MyService","onUnbind");
        return super.onUnbind(intent);
    }

    IMyAidlInterface.Stub mBinder = new IMyAidlInterface.Stub() {
        @Override
        public int AIDL_ADD(int a, int b) throws RemoteException {
            return a+b;
        }
    };

清单文件配置，exported一定要设置成true，表示此服务可以被其他地方调用，process设置成远程服务

<service
    android:name=".MyService"
    android:process=":remote"     
    android:enabled="true"
    android:exported="true">
    <intent-filter>
        <action android:name="reacheng.com.aidl_service.AIDL_Service"/>
    </intent-filter>
</service>

至此服务端配置完成，运行...

新建android工程：AIDL_Client（客户端）

拷贝AIDL_Service端的aidl文件夹到客户端工程在app/src/main下面

界面放置三个按钮，分别是绑定，解绑，获取结果

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

    <Button
        android:layout_centerInParent="true"
        android:id="@+id/bind_btn"
        android:onClick="click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="bind service"
        />

    <Button
        android:layout_centerInParent="true"
        android:layout_below="@id/bind_btn"
        android:id="@+id/unbind_btn"
        android:onClick="click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="unbind sercice"
        />

    <Button
        android:layout_centerInParent="true"
        android:layout_below="@id/unbind_btn"
        android:id="@+id/result_btn"
        android:onClick="click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="get result"
        />
</RelativeLayout>

client端主界面逻辑

public class MainActivity extends AppCompatActivity {
    private IMyAidlInterface iMyAidlInterface;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    
    private ServiceConnection connection = new ServiceConnection() {
        
        @Override
        public void onServiceDisconnected(ComponentName name) {
            Toast.makeText(MainActivity.this,"service is disconnected",Toast.LENGTH_LONG).show();
        }
        
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            
            iMyAidlInterface = IMyAidlInterface.Stub.asInterface(service);
            Toast.makeText(MainActivity.this,"service is connected",Toast.LENGTH_LONG).show();
        }
    };

    public void click(View view){
        
        Intent intent = new Intent("reacheng.com.aidl_service.AIDL_Service");
        //Android5.0后无法只通过隐式Intent绑定远程Service
        //需要通过setPackage()方法指定包名
        intent.setPackage("reacheng.com.aidl_service");
        switch (view.getId()){
            case R.id.bind_btn:
                bindService(intent, connection, Context.BIND_AUTO_CREATE);
                break;
            case R.id.unbind_btn:
                unbindService(connection);
                break;
            case R.id.result_btn:
                try {
                    //通过该对象调用在MyAIDLService.aidl文件中定义的接口方法,从而实现跨进程通信
                    final int result = iMyAidlInterface.AIDL_ADD(10,21);
                    Toast.makeText(MainActivity.this,"result for service is : "+result,Toast.LENGTH_LONG).show();
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
                break;
        }

    }
}

最后运行client 可以toast出结果...

至此，一个简单的aidl跨进程通讯完成，如果有错误，欢迎指正。