android上层alsa android aldl

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angel 2024-01-19 23:55:56

文章标签 android上层alsa android ooc ide 文章分类 Android 移动开发

一. AIDL 介绍.
二. AIDL简单应用.

Aidl_Server端
Aidl_Client端

三.注意事项

一. AIDL 介绍.

AIDL（Android接口描述语言）是一个IDL语言，它可以生成一段代码，可以是一个在Android设备上运行的两个进程使用内部通信进程进行交互。

如果你想在一个进程中（例如在一个Activity中）访问另一个进程中（例如service）某个对象的方法，你就可以使用AIDL来生成这样的代码来伪装传递各种参数。

稍微了解下几个常见的名词(IPC,匿名共享内存,Binder,Aidl,消息,广播,ContentProvider,Intent):

IPC是一种概念，即进程间通信；其它几个都是Android里的概念；

匿名共享内存(Anonymous Shared Memory):其作用之一即通过Binder进程间通信机制来实现进程间的内存共享。

Binder:Binder是对IPC的具体实行，是IPC的一种具体实现.其本质也是调用系统底层的共享内存实现.

AIDL:进程间的通信，速度快(系统底层直接是共享内存)，性能稳，效率高，一般进程间通信就用它. AIDL是Binder机制向外提供的接口，目的就是为了方便对Binder的使用；

消息(Messager)：Messenger本质也是AIDL，只是进行了封装，开发的时候不用再写.aidl文件,效率应该是和Aidl是一样的，与Aidl的区别在于Messager是线程安全的，而Aidl是非线程安全的，所以Aidl在使用的时候应该注意这个问题;

广播(BroadcastReceiver):只要注册了广播，都能收到，有点范围广，缺点速度慢必须在一定时间完成处理操作,同其他Android四大组件一样,都不能执行耗时操作;

ContentProvider:暴露app的数据访问接口，让其他应该访问app数据.同时也能通过ContentProvider来访问第三方的一些app数据(如通讯录,日历等暴露接口的应用);

Intent:Intent是最高层级的封装，实质是封装了对Binder的使用，当然Intent也常常在同一进程中调用，只是把两种方式封装在一起了.

android上层alsa android aldl_android

二. AIDL简单应用.

编写两个app应用程序,一个实现Aidl传递的Server端,一个实现Aidl的Client端:
aidl的Server端,接收Client端传过来的两个int值,定义一个加法计算的逻辑规则, 并返回 两个int数之和, return num1 + num2;
aidl的Client端,从界面用户输入两个int数,点击绑定Server端服务,点击计算,调用Server端加法逻辑,将返回结果 输入到用户界面展示,两数之和.

Aidl_Server端

android上层alsa android aldl_ooc_02

// IImoocAIDL.aidl
 package com.example.administrator.aidl_server.service;

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

interface IImoocAIDL {
     //计算num1 + num2
        int add(int num1,int num2);
}
// IImoocAIDL.aidl
 package com.example.administrator.aidl_server.service;

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

interface IImoocAIDL {
     //计算num1 + num2
        int add(int num1,int num2);
}

编译后会生成

public interface IImoocAIDL extends android.os.IInterface {
    /**
     * Local-side IPC implementation stub class.
     */
    public static abstract class Stub extends android.os.Binder implements com.example.administrator.aidl_server.service.IImoocAIDL {
            ...
            private static class Proxy implements com.example.administrator.aidl_server.service.IImoocAIDL {
            private android.os.IBinder mRemote;

            Proxy(android.os.IBinder remote) {
                mRemote = remote;
            }

            @Override
            public android.os.IBinder asBinder() {
                return mRemote;
            }

            public java.lang.String getInterfaceDescriptor() {
                return DESCRIPTOR;
            }

            @Override
            public int add(int num1, int num2) throws android.os.RemoteException {
                ...
            }
            
            ...
        }
            ...
    }
}
public interface IImoocAIDL extends android.os.IInterface {
    /**
     * Local-side IPC implementation stub class.
     */
    public static abstract class Stub extends android.os.Binder implements com.example.administrator.aidl_server.service.IImoocAIDL {
            ...
            private static class Proxy implements com.example.administrator.aidl_server.service.IImoocAIDL {
            private android.os.IBinder mRemote;

            Proxy(android.os.IBinder remote) {
                mRemote = remote;
            }

            @Override
            public android.os.IBinder asBinder() {
                return mRemote;
            }

            public java.lang.String getInterfaceDescriptor() {
                return DESCRIPTOR;
            }

            @Override
            public int add(int num1, int num2) throws android.os.RemoteException {
                ...
            }
            
            ...
        }
            ...
    }
}

android上层alsa android aldl_android_03

//om.example.administrator.aidl_server.IRemoteService

public class IRemoteService extends Service {
    public static final String TAG = "IRemoteService";
    //客户端绑定service时会执行
    @Override
    public IBinder onBind(Intent intent) {
        return iBinder;
    }

    private IBinder iBinder = new IImoocAIDL.Stub() {
        @Override
        public int add(int num1, int num2) throws RemoteException {
            Log.e(TAG,"收到了来自客户端的请求" + num1 + "+" + num2 );
            return num1 + num2;
        }

    };
}
public class IRemoteService extends Service {
    public static final String TAG = "IRemoteService";
    //客户端绑定service时会执行
    @Override
    public IBinder onBind(Intent intent) {
        return iBinder;
    }

    private IBinder iBinder = new IImoocAIDL.Stub() {
        @Override
        public int add(int num1, int num2) throws RemoteException {
            Log.e(TAG,"收到了来自客户端的请求" + num1 + "+" + num2 );
            return num1 + num2;
        }

    };
}

//AndroidManifest.xml

<application
    ...
        <service android:name=".IRemoteService"
            android:process=":remote"
            android:exported="true">
            <intent-filter>
                <action android:name="com.example.administrator.aidl_server"/>
            </intent-filter>
        </service>
    ...
</application>

Aidl_Client端

android上层alsa android aldl_ooc_04

com.example.administrator.aidl_client.MainActivity
public class MainActivity extends AppCompatActivity {
    public static final String TAG = "MainActivity";
    private EditText et_send_input,nub_1,nub_2;
    private TextView tv_send;
    private TextView tv_bind;
    private IImoocAIDL iImoocAIDLService;

    private ServiceConnection conn = new ServiceConnection() {

        //绑定服务，回调onBind()方法
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            iImoocAIDLService = IImoocAIDL.Stub.asInterface(service);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            iImoocAIDLService = null;
        }
    };


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

        bindService();

        et_send_input = findViewById(R.id.et_send_input);
        nub_1 = findViewById(R.id.nub_1);
        nub_2 = findViewById(R.id.nub_2);
        tv_send = findViewById(R.id.tv_send);
        tv_bind = findViewById(R.id.tv_bind);

        tv_send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    int nub1 = Integer.parseInt(nub_1.getText().toString().trim());
                    int nub2 = Integer.parseInt(nub_2.getText().toString().trim());

                    int result = iImoocAIDLService.add(nub1,nub2);
                    et_send_input.setText(result+"");
                }catch (Exception e){
                    e.printStackTrace();
                }

            }
        });

        tv_bind.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                bindService();
                Log.e(TAG,"bindService"+iImoocAIDLService);
            }
        });
    }

    private void bindService() {
        Intent intent = new Intent();
        //绑定服务端的service
        intent.setAction("com.example.administrator.aidl_server.IRemoteService");
        //新版本（5.0后）必须显式intent启动 绑定服务
        intent.setComponent(new ComponentName("com.example.administrator.aidl_server","com.example.administrator.aidl_server.IRemoteService"));
        //绑定的时候服务端自动创建
        bindService(intent,conn, Context.BIND_AUTO_CREATE);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(conn);
    }
}
com.example.administrator.aidl_client.MainActivity
public class MainActivity extends AppCompatActivity {
    public static final String TAG = "MainActivity";
    private EditText et_send_input,nub_1,nub_2;
    private TextView tv_send;
    private TextView tv_bind;
    private IImoocAIDL iImoocAIDLService;

    private ServiceConnection conn = new ServiceConnection() {

        //绑定服务，回调onBind()方法
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            iImoocAIDLService = IImoocAIDL.Stub.asInterface(service);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            iImoocAIDLService = null;
        }
    };


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

        bindService();

        et_send_input = findViewById(R.id.et_send_input);
        nub_1 = findViewById(R.id.nub_1);
        nub_2 = findViewById(R.id.nub_2);
        tv_send = findViewById(R.id.tv_send);
        tv_bind = findViewById(R.id.tv_bind);

        tv_send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    int nub1 = Integer.parseInt(nub_1.getText().toString().trim());
                    int nub2 = Integer.parseInt(nub_2.getText().toString().trim());

                    int result = iImoocAIDLService.add(nub1,nub2);
                    et_send_input.setText(result+"");
                }catch (Exception e){
                    e.printStackTrace();
                }

            }
        });

        tv_bind.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                bindService();
                Log.e(TAG,"bindService"+iImoocAIDLService);
            }
        });
    }

    private void bindService() {
        Intent intent = new Intent();
        //绑定服务端的service
        intent.setAction("com.example.administrator.aidl_server.IRemoteService");
        //新版本（5.0后）必须显式intent启动 绑定服务
        intent.setComponent(new ComponentName("com.example.administrator.aidl_server","com.example.administrator.aidl_server.IRemoteService"));
        //绑定的时候服务端自动创建
        bindService(intent,conn, Context.BIND_AUTO_CREATE);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(conn);
    }
}

layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <EditText
            android:id="@+id/nub_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inputType="number" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="+" />

        <EditText
            android:id="@+id/nub_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inputType="number" />

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

        <EditText
            android:id="@+id/et_send_input"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inputType="number" />
    </LinearLayout>

    <TextView
        android:id="@+id/tv_bind"
        android:layout_width="200dp"
        android:layout_height="55dp"
        android:layout_gravity="center"
        android:layout_marginBottom="15dp"
        android:background="@color/colorAccent"
        android:gravity="center"
        android:text="bind" />

    <TextView
        android:id="@+id/tv_send"
        android:layout_width="200dp"
        android:layout_height="55dp"
        android:layout_gravity="center"
        android:background="@color/colorAccent"
        android:gravity="center"
        android:text="计算" />


</LinearLayout>

android上层alsa android aldl_android_05