两个APP之间的通讯（客户端调用服务端里的音乐播放）

第一步：写一个Service类继承Sercice

package cn.itcast.aidl;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.os.RemoteException;
import cn.itcast.aidl.aidl.IDownloadService;
//定义一个类继承服务
public class ServiceBinder extends Service {
  private MediaPlayer mMediaPlayer;
  private TextFile textFile = new TextFile();
//定义一个内部类继承Stub
  public class TextFile extends IDownloadService.Stub {

    @Override
    //创建一个播放器
    public void playMusic(String path) {
      if (mMediaPlayer == null) {
        //创建播放器音乐资源或者路径
        mMediaPlayer = MediaPlayer.create(ServiceBinder.this, R.raw.a);
      } else {
        //重置播放器
        mMediaPlayer.reset();
        mMediaPlayer = MediaPlayer.create(ServiceBinder.this, R.raw.a);
      }
      mMediaPlayer.start();
    }
    //暂停播放器
    @Override
    public void pauseMusic() {
      if (mMediaPlayer == null) {
        mMediaPlayer.pause();
      }

    }

  }

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

}

以上把service写好了

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另外服务端里的aidl包名和文件内容也要在客户端的App里定义要完全一样

例：

服务端

package cn.itcast.aidl.aidl;
interface IDownloadService {
 void playMusic(String path);
 void pauseMusic();
}

这是在gen目录下保存时自动生成的一个aidl

客户端

package cn.itcast.aidl.aidl;
interface IDownloadService {
 void playMusic(String path);
 void pauseMusic();
}

都是在gen目录下生成aidl

当然也可以直接复制

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第二步：继续写一个客户端Activty继承Activty

package com.scxh.lizhong;

import android.app.Activity;
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.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import cn.itcast.aidl.aidl.IDownloadService;

public class MainActivity extends Activity {
  private Button mnButton;
  private IDownloadService mDownloadService;
  private  boolean isplayering=false;
  //新建一个服务连接
  private ServiceConnection mServiceConnection = new ServiceConnection() {
    //实现服务连接的两个方法
    @Override
    //第一个方法接收IBinder,用IBinder和服务进行连接
    public void onServiceConnected(ComponentName name, IBinder service) {

      mDownloadService = IDownloadService.Stub.asInterface(service);
      

    }

    @Override
    public void onServiceDisconnected(ComponentName name) {

      mDownloadService = null;

    }


  };

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mnButton = (Button) findViewById(R.id.buttonservice);
    //通过隐式调用
    Intent intent = new Intent();
    //和service里的androidmenifist注册的com.example.com.scxh.serviceBinder一致
    intent.setAction("com.example.com.scxh.serviceBinder");
    // startService(intent);
    
    bindService(intent, mServiceConnection, BIND_AUTO_CREATE);


    mnButton.setOnClickListener(new OnClickListener() {
      

      @Override
      public void onClick(View v) {
        if(isplayering){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
          isplayering=false;
          try {
            mDownloadService.pauseMusic();
          } catch (RemoteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
          
        }
        else{
          isplayering=true;
          try {
            mDownloadService.playMusic("");
          } catch (RemoteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
        }
      }
    });

  }

}

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把xml写上

<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_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="点击播放" 
        android:id="@+id/buttonservice"/>"

</RelativeLayout>