Android Messenger實現(xiàn)進程間雙向通信

更新時間：2021年05月21日 10:09:48 作者：Jason_Flash

這篇文章主要為大家詳細介紹了Messenger實現(xiàn)進程間雙向通信，文中示例代碼介紹的非常詳細，具有一定的參考價值，感興趣的小伙伴們可以參考一下

簡介

Messenger是安卓進程間通信 (IPC) 最為簡單的方式，可以實現(xiàn)進程間雙向通信。詳見官網(wǎng)介紹

代碼實現(xiàn)

服務端應用實現(xiàn)

MessengerService接收客戶端發(fā)送的消息：

package com.test.messengerservice;
import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;
import androidx.annotation.NonNull;

public class MessengerService extends Service {

    //接收客戶端的消息類型
    private static final int SEND_MESSENGER = 0;
    private static final int CONFIG_NET = 1;
    private static final int CANCEL = 2;

    //發(fā)送給客戶端的消息類型
    private static final int FIND_DEVICE = 10;

    public MessengerService() {
    }

    private Messenger messenger = new Messenger(new ServiceHandler());
    private static Messenger mClient;

    public class ServiceHandler extends Handler {

        @Override
        public void handleMessage(@NonNull Message msg) {
            // 處理消息
            switch(msg.what){
                case SEND_MESSENGER:
                    Log.d("service", "receive messenger");
                    mClient = msg.replyTo;
                    break;
                case CONFIG_NET:
                    Log.d("service", "config net task");
                    mClient = msg.replyTo;
                    break;
                case CANCEL:
                    Log.d("service", "cancel task");
                    mClient = msg.replyTo;
                    break;
                default:
                    break;
            }
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        Log.i("service", "service bind");
        return messenger.getBinder();
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("service", "service unbind");
        mClient = null;
        return super.onUnbind(intent);
    }

 //向客戶端發(fā)送消息
    public static void sendMessage() {
        if (null == mClient) {
            Log.d("service", "client is null");
            return;
        }
        try {
            Message message = Message.obtain(null, FIND_DEVICE);
            mClient.send(message);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

AndroidManifest.xml中注冊messenger服務：

<service
    android:name=".MessengerService"
    android:enabled="true"
    android:exported="true">
    <intent-filter>
        <action android:name="android.intent.action.MESSENGER"/>
    </intent-filter>
</service>

MainActivity中設(shè)置按鈕用于向客戶端主動發(fā)送消息：

package com.test.messengerservice;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private Button button;

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

        button = findViewById(R.id.findDeviceButton);
        button.setOnClickListener( new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                MessengerService.sendMessage();
            }
        });
    }
}

客戶端應用實現(xiàn)

MainActivity中綁定服務端的service，并設(shè)置向客戶端發(fā)送消息的按鈕：

package com.test.messengerclient;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    // 服務端的Messenger
    private Messenger mService;
    // 客戶端的Messenger
    private Messenger mMessenger;

    private Button buttonConfigNet;
    private Button buttonCancel;

    //發(fā)送給服務端的消息類型
    private static final int SEND_MESSENGER = 0;
    private static final int CONFIG_NET = 1;
    private static final int CANCEL = 2;

    //接收服務端的消息類型
    private static final int FIND_DEVICE = 10;

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

        //客戶端Messenger
        mMessenger = new Messenger(new ClientHandler());
        //綁定服務
        bindServiceInvoked();

  //設(shè)置點擊事件
        buttonConfigNet = findViewById(R.id.buttonConfigNet);
        buttonCancel = findViewById(R.id.buttonCancel);
        
        buttonConfigNet.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(mService != null) {
                    try {
                        Log.d("client", "send config net");
                        Message message = Message.obtain(null, CONFIG_NET);
                        message.replyTo = mMessenger;
                        mService.send(message);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        buttonCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(mService != null) {
                    try {
                        Log.d("client", "send cancel");
                        Message message = Message.obtain(null, CANCEL);
                        message.replyTo = mMessenger;
                        mService.send(message);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }

 //接收服務連接和斷開消息
    ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.i("client", "service connected");
            mService = new Messenger(service);

   //由于綁定后服務端沒有客戶端的Messenger ，綁定后先將客戶端Messenger發(fā)送給服務端
            if(mService != null) {
                try {
                    Log.d("client", "send messenger");
                    Message message = Message.obtain(null, SEND_MESSENGER);
                    message.replyTo = mMessenger;
                    mService.send(message);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.i("client", "service disconnected");
            mService = null;
        }
    };

 //從服務端接收消息
    public class ClientHandler extends Handler {

        @Override
        public void handleMessage(@NonNull Message msg) {
            switch (msg.what){
                case FIND_DEVICE:
                    Log.i("client", "find device");
                    break;
            }
        }
    }

 //綁定服務端的service
    private void bindServiceInvoked()
    {
        Intent intent = new Intent();
        intent.setAction("android.intent.action.MESSENGER");
        intent.setPackage("com.test.messengerservice");
        bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
    }
}

以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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