（七）Android中AIDL的应用与理解

一、跨应用启动Service

Intent serviceIntent=new Intent();
serviceIntent.setComponent(new ComponentName("com.example.shiyanshi.startservicefromanotherapp","com.example.shiyanshi.startservicefromanotherapp.AppService"));

跨应用启动Service时，Android5.0以前可以调用隐式Intent（通过在Service设置过滤器intent-filte），Android5.0之后只允许显示Intent来启动。首先创建Intent，之后调用setComponent函数来设置组件，该函数需要一个ComponentName的对象，ComponentName第一个参数为包名，第二个参数为包中的服务类名。

二、跨应用绑定Service并进行通信

app模块中：

1.MainActivity.java

package com.example.shiyanshi.startservicefromoterapp;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

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

        startService(new Intent(this,MyService.class));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        stopService(new Intent(this,MyService.class));
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

2.MyService.java

package com.example.shiyanshi.startservicefromoterapp;

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

public class MyService extends Service {
    public MyService() {
    }

    private String data="default data";
    private boolean flag;

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
//        throw new UnsupportedOperationException("Not yet implemented");

//返回的是AIDL中的接口，并且此处实现了接口函数的重定义
return new IAppRemoteServiceBinder.Stub() {
@Override
public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, String aString) throws RemoteException {

}

@Override
public void setData(String data) throws RemoteException {
MyService.this.data=data;
}
};

    }

    @Override
    public void onCreate() {
        super.onCreate();
        System.out.println("**********MyService onCreate************");

//该线程主要用于不断的输出该service种的数据data，data数据的值可以通过在anotherapp中调用setData函数进行设置，这样便实现了双方的通信

        new Thread(){
            @Override
            public void run() {
                super.run();
                flag=true;
                while (flag) {
                    System.out.println(data);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        System.out.println("***************MyService onDestroy********************");
        flag=false;
    }
}

//

不同的应用进行通信时需要创建aidl文件，并且在其中实现接口函数的定义

3.IAppRemoteServiceBinder.aidl

// IAppRemoteServiceBinder.aidl
package com.example.shiyanshi.startservicefromoterapp;

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

interface IAppRemoteServiceBinder {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat,
            double aDouble, String aString);    

void setData(String data); //用于两个应用程序之间进行通信的接口函数

}

anotherapp中：

1.布局文件

<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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="启动外部服务"
        android:id="@+id/btnStartService"
        android:layout_gravity="bottom" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="关闭外部服务"
        android:id="@+id/btnStopService"
        android:layout_gravity="center_vertical" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="绑定外部服务"
        android:id="@+id/btnBindService" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="解除绑定外部服务"
        android:id="@+id/btnUnbindService" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="同步数据到外部服务"
        android:id="@+id/btnSyncDataToAppService" />
    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="**************"
        android:id="@+id/editTextInput"/>

</LinearLayout>

2.MainActivity.java

package com.example.shiyanshi.anotherapp;

import android.app.Activity;
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.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;

import com.example.shiyanshi.startservicefromoterapp.IAppRemoteServiceBinder;

public class MainActivity extends Activity implements View.OnClickListener, ServiceConnection {

    Intent serviceIntent;
    private EditText editTextInput;
    private IAppRemoteServiceBinder binder;

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

        editTextInput=(EditText)findViewById(R.id.editTextInput);

        findViewById(R.id.btnStartService).setOnClickListener(this);
        findViewById(R.id.btnStopService).setOnClickListener(this);
        findViewById(R.id.btnBindService).setOnClickListener(this);
        findViewById(R.id.btnUnbindService).setOnClickListener(this);        

findViewById(R.id.btnSyncDataToAppService).setOnClickListener(this);

        serviceIntent=new Intent();
        serviceIntent.setComponent(new ComponentName("com.example.shiyanshi.startservicefromoterapp","com.example.shiyanshi.startservicefromoterapp.MyService"));

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btnStartService:
                startService(serviceIntent);
                break;
            case R.id.btnStopService:
                stopService(serviceIntent);
                break;
            case R.id.btnBindService:               

bindService(serviceIntent,this, Context.BIND_AUTO_CREATE);

                break;
            case R.id.btnUnbindService:
                unbindService(this);
                binder=null;
                break;           

case R.id.btnSyncDataToAppService:
if (binder!=null){
try {
binder.setData(editTextInput.getText().toString());
} catch (RemoteException e) {
e.printStackTrace();
}
}
break;

        }

    }

    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        System.out.println("*******onServiceConnected*************");       

//不能直接强制类型转换，因为两个类型处于不同的应用程序中
binder=IAppRemoteServiceBinder.Stub.asInterface(iBinder);

    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }
}

3.文件目录结构，将在App模块中创建的aidl文件复制到了anotherapp中，首先穿件aidl目录，然后在aidl目录中创建app中的程序包（com.example.shiyanshi.startservicefromoterapp），之后将app中的IAppRemoteServiceBinder.aidl文件复制到该程序包