AIDL(1)--定义以及简单使用

傷城~ 2023-06-16 05:59 17阅读 0赞

## AIDL ##

AIDL:Android 接口定义语言 (AIDL) 与您可能使用过的其他接口语言 (IDL) 类似。您可以利用它定义客户端与服务均认可的编程接口，以便二者使用进程间通信 (IPC) 进行相互通信。在 Android 中，一个进程通常无法访问另一个进程的内存。因此，为进行通信，进程需将其对象分解成可供操作系统理解的原语，并将其编组为可供您操作的对象。编写执行该编组操作的代码较为繁琐，因此 Android 会使用 AIDL 为您处理此问题。

> 注意：只有在需要不同应用的客户端通过 IPC 方式访问服务，并且希望在服务中进行多线程处理时，您才有必要使用 AIDL。如果您无需跨不同应用执行并发 IPC，则应通过实现 Binder 来创建接口；或者，如果您想执行 IPC，但不需要处理多线程，请使用 Messenger 来实现接口。无论如何，在实现 AIDL 之前，请您务必理解绑定服务。

您可以通过 IPC 接口，将某个类从一个进程发送至另一个进程。不过，您必须确保 IPC 通道的另一端可使用该类的代码，并且该类必须支持 Parcelable 接口。支持 Parcelable 接口很重要，因为 Android 系统能通过该接口将对象分解成可编组至各进程的原语。在第二部分介绍这块．

## 代码结构 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hlbGxvd29ybGRkbQ_size_16_color_FFFFFF_t_70]

## demo ##

aidl文件:

// IMyAidlInterface.aidl
    package com.example.buringteng.myapplication;
    
    // Declare any non-default types here with import statements
    
    interface IMyAidlInterface {
        /**
         * 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);
    }

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.buringteng.myapplication">
    
        <application
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/AppTheme">
            <activity
                android:name=".MainActivity"
                android:label="@string/app_name"
                android:theme="@style/AppTheme.NoActionBar">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
    
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
    
            <service
                android:name=".RemoteService"
                android:enabled="true"
                android:exported="true" >
    
            </service>
    
        </application>
    
    </manifest>

MainActivity.java

public class MainActivity extends AppCompatActivity {
        //The interface will be calling in service
        IMyAidlInterface iRemoteService = null;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);
    
            FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
            fab.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                            .setAction("Action", null).show();
                    Intent intent = new Intent(MainActivity.this,RemoteService.class);
                   intent.setAction(IMyAidlInterface.class.getName());
                   bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
                }
            });
        }
        private ServiceConnection mConnection = new ServiceConnection() {
            // Called when the connection with the service is established
            public void onServiceConnected(ComponentName className, IBinder service) {
                Log.e("aidl test", "Service connected");
                // Following the example above for an AIDL interface,
                // this gets an instance of the IMyAidlInterface, which we can use to call on the service
                iRemoteService = IMyAidlInterface.Stub.asInterface(service);
             //   iRemoteService.basicType;
                try {
                    iRemoteService.basicTypes(1, 2L,false, 7.72f,
                    6.77f, "Hello world");
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
            // Called when the connection with the service disconnects unexpectedly
            public void onServiceDisconnected(ComponentName className) {
                Log.e("aidl test", "Service has unexpectedly disconnected");
                iRemoteService = null;
            }
        };
    
        @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);
        }
    
    }

RemoteService.java

public class RemoteService extends Service {
        @Override
        public void onCreate() {
            super.onCreate();
        }
        @Override
        public IBinder onBind(Intent intent) {
            // Return the interface
            Log.e("onBind", "invoke");
            return binder;
        }
    
       private final IMyAidlInterface.Stub binder = new IMyAidlInterface.Stub() {
            public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat,
                                   double aDouble, String aString){
                Log.e("Stub test", ""+anInt);
            }
        };
    }

## 补充 ##

android:enable 用于执行service能否被实例化  
android.exported 用于制定其他应用程序组件能否调用service或者与其交互．true表示能，false表示不能．

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