Broadcast的动态注册与静态注册和Notification的使用

一、    实现内容

二、实验基本

广播的详细过程
 发送广播：在需要发送信息的地方，把要发送的信息和用于过滤的信息(如Action、Category)装入一个Intent对象，调用Context.sendBroadcast() 方法把Intent对象以广播方式发送出去。
 接收广播：当Intent发送以后，所有已经注册的BroadcastReceiver会检查注册时的IntentFilter是否与发送的Intent相匹配，若匹配则就会调用BroadcastReceiver的void onReceive(Context curContext, Intent broadcastMsg)方法。

注册BroadcastReceiver

有两种方式:一种方式是，静态的在AndroidManifest.xml中用<receiver>标签生命注册，并在标签内用<intent- filter>标签设置过滤器。

另一种方式是，动态的在代码中先定义并设置好一个 IntentFilter 对象，然后在需要注册的地方调Context.registerReceiver()方法，如果取消时就调用 Context.unregisterReceiver()方法。如果用动态方式注册的BroadcastReceiver的Context对象被销毁时，BroadcastReceiver也就自动取消注册了。（特别注意，有些可能需要后台监听的，如短信消息）

另外，若在使用sendBroadcast()的方法是指定了接收权限，则只有在AndroidManifest.xml中用<uses- permission>标签声明了拥有此权限的BroascastReceiver才会有可能接收到发送来的Broadcast。同样，若在注册BroadcastReceiver时指定了可接收的Broadcast的权限，则只有在包内的AndroidManifest.xml中 用<uses-permission>标签声明了，拥有此权限的Context对象所发送的Broadcast才能被这个 BroadcastReceiver所接收

BroadcastReceiver开发过程如下
1. 开发BroadcastReceiver子类，重写onReceive()
2. 注册BroadcastReceiver对象
3. 将要广播的消息封装到Intent中，调用方法发送出去
4. 通过IntentFilter对象过滤Intent，处理信息名称匹配的广播

Notification可以提供持久的通知，位于手机最上层的状态通知栏中。用手指按下状态栏，并从手机上方向下滑动，就可以打开状态栏查看提示消息。开发Notification
主要涉及以下3个类：
1. Notification.Builder：用于动态的设置Notification的一些属性。
2. NotificationManager：负责将Notification在状态显示出来和取消；
3. Notification：设置Notification的相关属性。

三、代码

MainActivity.Java

package com.example.hp.lab4;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

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

        final Button static_button=(Button)findViewById(R.id.static_button);
        final Button dynamic_button=(Button)findViewById(R.id.dynamic_button);

        static_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, StaticActivity.class);
                startActivity(intent);
            }
        });
        dynamic_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, DynamicActivity.class);
                startActivity(intent);
            }
        });
    }
}

StaticActivity.Java

package com.example.hp.lab4;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by HP on 2016/10/14.
 */
public class StaticActivity extends Activity {

    private List<Fruit> fruit_list =new ArrayList<Fruit>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.static_layout);


        final ListView list_id=(ListView) findViewById(R.id.listview);
        initFruit();
        final FruitAdapter fruitAdapter=new FruitAdapter(this,fruit_list);
        list_id.setAdapter(fruitAdapter);

        list_id.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent=new Intent("com.example.lab4.staticreceiver");
                intent.putExtra("id",fruit_list.get(position).getResourceId());
                intent.putExtra("name",fruit_list.get(position).getName());
                sendBroadcast(intent);
            }
        });



    }

    void initFruit(){
        fruit_list.add(new Fruit(R.mipmap.apple,"Apple"));
        fruit_list.add(new Fruit(R.mipmap.banana,"Banana"));
        fruit_list.add(new Fruit( R.mipmap.cherry,"Cherry"));
        fruit_list.add(new Fruit(R.mipmap.coco,"Coco"));
        fruit_list.add(new Fruit( R.mipmap.kiwi,"Kiwi"));
        fruit_list.add(new Fruit( R.mipmap.orange,"Orange"));
        fruit_list.add(new Fruit(R.mipmap.pear,"Pear"));
        fruit_list.add(new Fruit( R.mipmap.strawberry,"Strawberry"));
        fruit_list.add(new Fruit( R.mipmap.watermelon,"Watermelon"));
    }
}

StaticReceiver.java

package com.example.hp.lab4;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;

import java.util.Random;

/**
 * Created by HP on 2016/10/14.
 */
public class StaticReceiver extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        Bundle bundle=intent.getExtras();
        //由Icon的id得到Bitmap
        Bitmap bitmap= BitmapFactory.decodeResource(context.getResources(),bundle.getInt("id"));
        //通过getSystemService（）方法得到NotificationManager对象，它负责管理发送通知、清除通知等一系列的对通知的管理工作。
        NotificationManager notificationManager=(NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
        Notification.Builder builder=new Notification.Builder(context);
        builder.setContentTitle("静态广播")//设置通知栏标题
                .setContentText(bundle.getString("name"))//设置通知栏显示内容
                .setLargeIcon(bitmap)//通知栏的大Icon
                .setTicker("您有一条新信息.")//通知首次出现在通知栏，带上升动画效果
                .setSmallIcon(bundle.getInt("id"))
                .setAutoCancel(true);//用户点击面板就让通知自动取消
        Intent intent2 = new Intent(context, MainActivity.class);//点击时跳转的intent，跳转到MainActivity
        PendingIntent contentIntent = PendingIntent.getActivity(context, 0, intent2, 0);//PendingIntent授予启动Mainactivity的权利。
        builder.setContentIntent(contentIntent);
        Notification notify=builder.build();//绑定通知，
        notificationManager.notify(0,notify);//显示通知
    }
}

FruitAdapter.java

package com.example.hp.lab4;

import android.content.Context;
import android.media.Image;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

/**
 * Created by HP on 2016/10/14.
 */

public class Fruit {
    private int resourceId;
    private String name;

    public Fruit(int resourceId,String name ){
        this.resourceId=resourceId;
        this.name=name;
    }
    public String getName(){
        return name;
    }

    public int getResourceId(){
        return resourceId;
    }

}

public class FruitAdapter extends BaseAdapter {

    private Context context;
    private List<Fruit> listItem;

    public FruitAdapter(Context context,List<Fruit> listItem){
        this.context=context;
        this.listItem=listItem;
    }

    @Override
    public int getCount(){
        if(listItem==null){
            return 0;
        }
        return listItem.size();
    }
    //获得某个数据
    @Override
    public Fruit getItem(int i){
        if(listItem==null){
            return null;
        }
        return listItem.get(i);
    }
    //获得数据项的位置
    @Override
    public long getItemId(int i){
        return i;
    }

    @Override

    //获得数据项的布局样式，最重要的一个方法
    public View getView(int i, View view, ViewGroup viewGroup){
        if(view==null){
            //通过inflate的方法加载布局，
            view= LayoutInflater.from(context).inflate(R.layout.item,null);
        }
        //得到单项布局中textview的id
        ImageView fruit_image=(ImageView) view.findViewById(R.id.fruit_image);
        TextView fruit_name=(TextView) view.findViewById(R.id.fruit_name);

        //从数据列表中取出对应的数据并赋值给对应的textview
        fruit_image.setImageResource(listItem.get(i).getResourceId());
        fruit_name.setText(listItem.get(i).getName());
        return view;
    }


}

DynamicActivity.java

package com.example.hp.lab4;

import android.app.Activity;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

/**
 * Created by HP on 2016/10/14.
 */
public class DynamicActivity extends Activity {

    private boolean isRegistered = false;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dynamic_layout);
        final Button register=(Button)findViewById(R.id.register);
        final Button send=(Button)findViewById(R.id.send);
        final EditText editText=(EditText) findViewById(R.id.edittext);
        final DynamicReceiver dynamicReceiver=new DynamicReceiver();
        register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(DynamicActivity.this.isRegistered){
                    register.setText("Register Broadcast");//设置register按键的内容
                    unregisterReceiver(dynamicReceiver);//注销广播
                    DynamicActivity.this.isRegistered=false;
                }
                else{
                    register.setText("Unregister Broadcast");
                    //注册广播，以及广播的action
                    registerReceiver(dynamicReceiver,new IntentFilter("com.example.lab4.dynamicreceiver"));
                    DynamicActivity.this.isRegistered=true;

                }
            }
        });
        send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(isRegistered){
                    Intent intent=new Intent("com.example.lab4.dynamicreceiver");
                    Bundle bundle=new Bundle();
                    bundle.putString("message",editText.getText().toString());
                    intent.putExtras(bundle);
                    DynamicActivity.this.sendBroadcast(intent);
                }

            }
        });
    }
}

DynamicReciver.java

package com.example.hp.lab4;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Icon;
import android.os.Bundle;

import java.io.InputStream;

/**
 * Created by HP on 2016/10/14.
 */
public class DynamicReceiver extends BroadcastReceiver{
    private static final String DYNAMICACTION="com.example.lab4.dynamicreceiver";//约定俗成，包名+intent.action+MyReceiver
    @Override
    public void onReceive(Context context, Intent intent){
        if(intent.getAction().equals(DYNAMICACTION)){//对Action进行判断
            Bitmap bitmap= BitmapFactory.decodeResource(context.getResources(),R.mipmap.dynamic);
            Bundle bundle=intent.getExtras();
            NotificationManager notificationManager=(NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
            Notification.Builder builder=new Notification.Builder(context);
            builder.setContentTitle("动态广播")
                    .setContentText(bundle.getString("message"))
                    .setLargeIcon(bitmap)
                    .setTicker("您有一条新信息.")
                    .setSmallIcon(R.mipmap.dynamic)
                    .setAutoCancel(false);
            Intent intent2 = new Intent(context, MainActivity.class);
            PendingIntent contentIntent = PendingIntent.getActivity(context, 0, intent2, 0);
            builder.setContentIntent(contentIntent);
            Notification notify=builder.build();
            notificationManager.notify(0,notify);
        }
    }
}

项目仓库：https://github.com/luqx3/Broadcast