app实现调用aidl接口

1. 创建aidl文件

在app/src/main/aidl目录下创建一个名为IHelloWorld.aidl的文件，内容如下：

package com.example.helloworld;

interface IHelloWorld {
    String sayHello();
    void setHello(String hello);
}

2. 实现aidl接口

在app/src/main/java目录下创建一个名为HelloWorldService的Java类，实现IHelloWorld接口，代码如下：

package com.example.helloworld;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;

public class HelloWorldService extends Service {

    private String mHello = "Hello World!";

    private final IHelloWorld.Stub mBinder = new IHelloWorld.Stub() {
        @Override
        public String sayHello() throws RemoteException {
            return mHello;
        }

        @Override
        public void setHello(String hello) throws RemoteException {
            mHello = hello;
        }
    };

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

3. 注册服务

在app/src/main/AndroidManifest.xml文件中注册服务，代码如下：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.helloworld">

    <application
        android:allowBackup="true"
        android:label="@string/app_name"
        android:icon="@mipmap/ic_launcher"
        android:theme="@style/AppTheme">

        <service android:name=".HelloWorldService"
            android:exported="true">
            <intent-filter>
                <action android:name="com.example.helloworld.IHelloWorld" />
            </intent-filter>
        </service>

    </application>

</manifest>

4. 调用aidl接口

在app/src/main/java目录下创建一个名为MainActivity的Java类，代码如下：

package com.example.helloworld;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

    private IHelloWorld mHelloWorld;

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

        IBinder binder = getService("com.example.helloworld.IHelloWorld");
        mHelloWorld = IHelloWorld.Stub.asInterface(binder);

        try {
            String hello = mHelloWorld.sayHello();
            Log.d(TAG, "sayHello: " + hello);

            mHelloWorld.setHello("Hello Android!");
            hello = mHelloWorld.sayHello();
            Log.d(TAG, "sayHello: " + hello);

        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    private IBinder getService(String serviceName) {
        IBinder binder = null;
        Intent intent = new Intent(serviceName);
        intent.setPackage(getPackageName());
        ServiceConnection conn = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                binder = service;
            }

            @Override
            public void onServiceDisconnected(ComponentName name) {

            }
        };
        bindService(intent, conn, Context.BIND_AUTO_CREATE);
        return binder;
    }
}

运行app，查看Logcat中的输出信息，即可看到调用aidl接口的结果。