安卓中AIDL的使用方法快速入门

时间:2022-03-29 23:20:04

1.AIDL是什么?

AIDL全称是Android Interface Definition Language,即安卓接口定义语言。

2.AIDL是用来做什么的?(为什么要有AIDL)

AIDL是用来进行进程间通信(IPC全称interprocess communication )的。

3.如何使用AIDL?

对于AIDL的使用,

服务端需要完成的任务是:

 

①.写一个xxxx.aidl文件

②.写一个Service并在AndroidManifest.xml中声明它。(注意:这个service里面有一个引用了实现xxxx.Stub抽象类的IBinder对象,这个对象将在service的onBind方法里面返回给调用者)

客户端的任务:

①.使用和服务端相同的那个aidl文件

②.在实现了ServiceConnection接口的onServiceConnected(ComponentName name, IBinder service)方法中调用myvar = testidl.Stub.asInterface(service)保存得到的对象,其中myvar是xxxx的类型

这么说还是不够清楚,下面直接上代码。

首先是服务端的

//testidl.idl文件的内容
package com.example.xxnote;

interface testidl {
void TestFunction(int anInt, long aLong, boolean aBoolean, float aFloat,
double aDouble, String aString);
}

 

//myaidlservice.java文件的内容
package com.example.xxnote;

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

public class myaidlservice extends Service {

private final IBinder myStub = new testidl.Stub() {

@Override
public void TestFunction(int anInt, long aLong, boolean aBoolean,
float aFloat, double aDouble, String aString)
throws RemoteException {
// TODO Auto-generated method stub
System.out.println("basicTypes()");
System.err.println("Service"+anInt + "," + aLong + "," + aBoolean + ","
+ aFloat + "," + aDouble + "," + aString);
}
};

@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
System.out.println("AIDL Service onBind, and return IBinder");
return myStub;
}

@Override
public void onCreate() {
// TODO Auto-generated method stub
System.out.println("AIDL Service onCreate");
super.onCreate();
}

@Override
public boolean onUnbind(Intent intent) {
// TODO Auto-generated method stub
System.out.println("AIDL Service onUnbind");
return super.onUnbind(intent);
}

@Override
public void onDestroy() {
// TODO Auto-generated method stub
System.out.println("AIDL Service onDestroy");
super.onDestroy();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
System.out.println("AIDL Service onStartCommand");
return super.onStartCommand(intent, flags, startId);
}
}

 

1 <!--  AndroidManifest.xml 的 application 标签的内容-->
2 <service android:name="myaidlservice">
3 <intent-filter >
4 <action android:name="zhenshi.mafan.qisia.aidl"/>
5 </intent-filter>
6 </service>

 对于客户端,首先需要把aidl文件复制到相应的目录本例中是src/com/example/xxnote/testidl.aidl

package com.example.xxnote.callaidl;

import com.example.xxnote.testidl;

import android.R.bool;
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;
public class MainActivity extends Activity {

private testidl mytTestidl;
private ServiceConnection connection;
private boolean isServiceConnected;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
connection = new ServiceConnection() {


@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
System.out.println("Client onServiceDisconnected");
}

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// TODO Auto-generated method stub
System.out.println("Client onServiceConnected");
mytTestidl = testidl.Stub.asInterface(service);
isServiceConnected = true;
}
};
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
    
//关闭服务按钮的事件
public void StopMyService(View v) {
System.out.println("StopMyService");
isServiceConnected = false;
unbindService(connection);
mytTestidl = null;
}
     //开启服务按钮的事件
public void StartMyService(View v) {
System.out.println("before bindService()");
bindService(
new Intent().setAction("zhenshi.mafan.qisia.aidl"),
connection,
Context.BIND_AUTO_CREATE);
/**
* bindService是异步的所以执行bindService方法的同时也开始执行下面的方法了,
* Debug跟踪了一下程序发现貌似Activity里面所有的方法都是在主线程的loop()方法
* 循环里面以消息队列里面的一个消息的样子执行的,也就是此处的StartMyService方
* 法对应的消息处理完(此函数返回)后,才能处理下一个消息,即执行onServiceConnected回调方法
*
* 试验了一下,StopMyService里面把mytTestidl赋值为null,即每次解除服务绑定后都重置mytTestidl为null
* 果然每次下面的语句:
* mytTestidl.basicTypes(1, 1, true, 100.0f, 200.0, "ssss");
* 都报空指针异常
*/

try {
mytTestidl.TestFunction(1, 1, true, 100.0f, 200.0, "ssss");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

  

这里还有一个需要注意的地方,就是bindService方法 的时候用到的intent,通过setAction可以成功启动服务,用setClassName就不能,不知道什么原因,暂时留待以后解决。

找到原因了,用setClassName的时候必须使用全限定类名,如:new Intent().setClassName("com.example.client.callaidl", "com.example.client.callaidl.testact")