全局事件-广播(Broadcast)

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什么是广播

广播是Android SDK的四大组件中唯一需要别动接收数据的组件。也就是说对于Activity、ContentProvider和Service都可以主动调用,并获取返回数据。而负责接收Broadcast数据的接收器却永远不知道什么时候可以接收到广播。从这种表现形式上看,很像面向对象中的事件(Event),对于事件(onClick、onKeydown)来说,从来不会预知用户什么时候触发他们,只能默默的等待不可预知的事件发生。因此,广播也可以被成为全局事件。


接收系统广播

短信拦截(静态注册)

1 编写广播接收器类,继承自android.content.BroadcastReceiver类

ShortMessageReceiver.java

package com.turing.base.activity.broadcastDemo;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.telephony.SmsMessage;import android.widget.Toast;import com.apkfuns.logutils.LogUtils;import java.util.Set;public class ShortMessageReceiver extends BroadcastReceiver {    private Handler handler ;    public ShortMessageReceiver() {    }    public ShortMessageReceiver(Handler handler) {        this.handler = handler ;    }    @Override    public void onReceive(Context context, Intent intent) {        Bundle bundle = intent.getExtras();        if (bundle != null) {            Set<String> keys = bundle.keySet();            //查看收的广播包含哪些数据            for (String key : keys) {                LogUtils.e("bundele中的数据" + key);            }            // 获取收到的短信            Object[] objArray = (Object[]) bundle.get("pdus");            String message = parseMessageFromRawData(objArray);            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();            Message msg = new Message();            msg.what = 1 ;            msg.obj = message;            handler.sendMessage(msg);            /**            // 定义封装短信内容的SmsMessage对象数组            SmsMessage[] message = new SmsMessage[objArray.length];            // 循环处理收到的所有短信            for (int i = 0; i < objArray.length; i++) {                // 将每条短信数据转换成SendMessage对象                message[i] = SmsMessage.createFromPdu((byte[]) objArray[i]);                // 获取发送短信的电话号码和短信内容                String messageInfo = "手机号:" + message[i].getOriginatingAddress() + "\n";                messageInfo += "短信内容:" + message[i].getDisplayMessageBody();                //做个简单的展示                Toast.makeText(context, messageInfo, Toast.LENGTH_SHORT).show();            }             **/        }    }    public  String  parseMessageFromRawData(Object[] pdus) {        if (pdus == null) return null;        try {            StringBuilder message = new StringBuilder();            for (Object pdu : pdus) {                SmsMessage smsMessage = SmsMessage.createFromPdu((byte[]) pdu);                if (smsMessage == null) continue;                message.append("源号码:" + smsMessage.getOriginatingAddress() + ",内容:" +smsMessage.getDisplayMessageBody());            }            return message.toString();        } catch (Exception e) {            LogUtils.e( "SMSBroadcastReceiver read sms failed", e);        } catch (OutOfMemoryError oom) {            LogUtils.e( "SMSBroadcastReceiver caused OOM =_=!", oom);            //为了避免后续操作出现问题,gc一下            System.gc();            System.gc();        }        return null;    }}

清单文件配置Receiver

 <receiver            android:name=".activity.broadcastDemo.ShortMessageReceiver"            android:enabled="true"            android:exported="true">            <intent-filter>                <action android:name="android.provider.Telephony.SMS_RECEIVED" />            </intent-filter>        </receiver>

清单文件配置权限

    <uses-permission android:name="android.permission.RECEIVE_SMS" />

注意事项

  • 如果不知道广播中包含哪些数据,可以从Bundle.keySet()方法中获取这些数据的key,将其输出到Logcat中查看,如上述代码所示
  • 由于接受的短信内容是以字节数组的形式保存的,为了方便使用这些数据,需要使用SmsMessage.createFromPdu方法将这些字节数据组成的数据转换为SmsMessage对象
  • SmsMessage建议使用android.telephony.SmsMessage中的。
  • 由于接收器可能接收多条短信,因此通过pdus返回了一个短信数组。
  • 必须要指定<action android:name="android.provider.Telephony.SMS_RECEIVED" /> 我们编写的短信接收器才可以接收系统的短信广播,切记
  • 配置权限android.permission.RECEIVE_SMS
  • 即使注册广播接收器的程序关闭,接收器仍然会接收到广播,除非从模拟器或者手机中卸载程序或者注销接收器,否则无法阻止接收器接收广播

用代码注册广播接收器

如果在清单文件中配置广播接收器,程序安装后就会自动注册广播接收器,如果想在适当的时候注册广播接收器,在使用完成之后将其注销就需要使用Java代码来操作了。

注册和取消方法

注册广播接收器的方法是 registerReceiver,注销的方法是unregisterReceiver,定义如下:

 public Intent registerReceiver(        BroadcastReceiver receiver, IntentFilter filter) public void unregisterReceiver(BroadcastReceiver receiver) 

其中receiver表示广播接收器对象,
filter参数相当于设置intent-filter标签中的内容。

Code

package com.turing.base.activity.broadcastDemo;import android.app.Activity;import android.content.IntentFilter;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;import com.turing.base.R;public class SmsMessageAct extends Activity implements View.OnClickListener {    private EditText et_phone, et_msg;    private Button btn_registerReceiver, btn_unRegisterReceiver;    private ShortMessageReceiver shortMessageReceiver;    private Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            switch (msg.what) {                case 1:                    String message = (String) msg.obj;                    String pre = "源号码:";                    String suf = ",内容:";                    et_phone.setText(message.substring((message.indexOf(pre) + pre.length()), message.indexOf(suf)));                    et_msg.setText(message.substring(message.indexOf(suf) + suf.length(), message.length()));                    break;                default:                    break;            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_sms_message);        initView();        initEvents();        // 创建广播接收器的对象        shortMessageReceiver = new ShortMessageReceiver(handler);    }    private void initEvents() {        btn_registerReceiver.setOnClickListener(this);        btn_unRegisterReceiver.setOnClickListener(this);    }    private void initView() {        et_phone = (EditText) findViewById(R.id.id_et_phone);        et_msg = (EditText) findViewById(R.id.id_et_msg);        btn_registerReceiver = (Button) findViewById(R.id.id_btn_registerReceiver);        btn_unRegisterReceiver = (Button) findViewById(R.id.id_btn_unRegisterReceiver);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.id_btn_registerReceiver:                registerReceiver(shortMessageReceiver, new IntentFilter("android.provider.Telephony.SMS_RECEIVED"));                Toast.makeText(this, "动态注册广播接收器成功", Toast.LENGTH_SHORT).show();                break;            case R.id.id_btn_unRegisterReceiver:                unregisterReceiver(shortMessageReceiver);                Toast.makeText(this, "动态注销短信广播接收器over", Toast.LENGTH_SHORT).show();                break;            default:                break;        }    }    @Override    protected void onPause() {        super.onPause();        if (shortMessageReceiver != null) {            unregisterReceiver(shortMessageReceiver);            Toast.makeText(this, "Activity onPause ,注销短信广播接收器over", Toast.LENGTH_SHORT).show();        }    }}

广播的优先级

android:priority

通过intent-filter标签的android:priority属性可以设置接收器的调用优先级,该属性值属于一个整数,数值越大,优先级越高。

Code

 <receiver android:name=".activity.service.StartupReceiver">            <intent-filter android:priority="100">                <action android:name="android.intent.action.BOOT_COMPLETED" />            </intent-filter>        </receiver>
  • 如果不设置优先级别,对于同一个应用程序中的广播接收器会按照在Manifest清单文件中定义的顺序调用。

    • 广播的优先级只是对同步处理方式起作用,如果在接收器中使用了异步处理方式,则调用的顺序除了和优先级有关,还和Android系统的线程调用有关。

来去电拦截

广播动作

监听电话状态以用于拦截来去电,来电(监听电话状态)和去电的广播动作如下:

  • 来电:android.intent.action.PHONE_STATE
  • 去电:android.intent.action.NEW_OUTGOING_CALL

来电可以分解为3个状态:未接电话时的响铃,接听电话 和挂断电话(可能是对方挂断,也可能是自己挂断)

监听这三个状态的代码如下(使用静态方式注册的广播):

CallInReceiver:

package com.turing.base.activity.broadcastDemo;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.telephony.TelephonyManager;import android.view.Gravity;import android.view.LayoutInflater;import android.view.View;import android.widget.PopupWindow;import android.widget.TextView;import android.widget.Toast;import com.turing.base.R;public class CallInReceiver extends BroadcastReceiver {    private static Object obj;    public CallInReceiver() {    }    @Override    public void onReceive(Context context, Intent intent) {        // 获取电话管理服务,以便获取电话的状态        TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);        switch (telephonyManager.getCallState()) {            case TelephonyManager.CALL_STATE_RINGING: // 响铃                String incomingNumber = intent.getStringExtra("incoming_number");                Toast.makeText(context, "电话响铃中......", Toast.LENGTH_SHORT).show();                //showPopupWindowToast(context,incomingNumber);                break;            case TelephonyManager.CALL_STATE_OFFHOOK: //接听电话                Toast.makeText(context, "电话已接通......", Toast.LENGTH_SHORT).show();                break;            case TelephonyManager.CALL_STATE_IDLE:// 挂断电话                Toast.makeText(context, "挂断电话......", Toast.LENGTH_SHORT).show();                //closeToast();            default:                break;        }    }    /**     * 使用反射,此Toast不会关闭     *     * @param context     * @param msg     *///    public static void showToast(Context context, String msg) {//        Toast toast = Toast.makeText(context, msg, Toast.LENGTH_SHORT);//        toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL, 0, 0);//        try {//            Field field = toast.getClass().getDeclaredField("mTN");//            field.setAccessible(true);//            obj = field.get(toast);//            Method method = obj.getClass().getDeclaredMethod("show", null);//            method.invoke(obj, null);//        } catch (Exception e) {//        }////    }    /**     * 通过此方法关闭那个不可关闭的Toast     *///    public static void closeToast() {//        if (obj != null) {//            try {//                Method method = obj.getClass().getDeclaredMethod("hide", null);//                method.invoke(obj, null);//            } catch (Exception e) {//            }////        }//    }    public static void showPopupWindowToast(Context context, String incomingNumber) {        LayoutInflater inflater  = LayoutInflater.from(context);        View view = inflater.inflate(R.layout.activity_popupwd_toast, null);        TextView textView = (TextView)view.findViewById(R.id.tvMsg);        textView.setText("电话号码:" + incomingNumber);        final PopupWindow popupWindow = new PopupWindow(view,500 ,100);        popupWindow.setTouchable(false);        popupWindow.showAtLocation(view, Gravity.CENTER_HORIZONTAL,20 ,0);        // 设置定时器,5秒后自动关闭        android.os.Handler handler = new android.os.Handler();        handler.postDelayed(new Runnable() {            @Override            public void run() {                popupWindow.dismiss();            }        } , 5*1000);    }}

CallOutReceiver

package com.turing.base.activity.broadcastDemo;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class CallOutReceiver extends BroadcastReceiver {    public CallOutReceiver() {    }    @Override    public void onReceive(Context context, Intent intent) {        // 获取去电号码        String outComingNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);        // showToast        Toast.makeText(context, "去电......" + outComingNumber, Toast.LENGTH_SHORT).show();        //CallInReceiver.showPopupWindowToast(context, outComingNumber);    }}
 <!-- 来电 -->        <receiver            android:name=".activity.broadcastDemo.CallInReceiver"            android:enabled="true"            android:exported="true">            <intent-filter>                <action android:name="android.intent.action.PHONE_STATE" />            </intent-filter>        </receiver>        <!-- 去电 -->        <receiver            android:name=".activity.broadcastDemo.CallOutReceiver"            android:enabled="true"            android:exported="true">            <intent-filter>                <action android:name="android.intent.action.NEW_OUTGOING_CALL" />            </intent-filter>        </receiver>

设置权限

  <uses-permission android:name="android.permission.READ_PHONE_STATE" />    <uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" />

截获屏幕休眠与唤醒

按手机上的挂断按钮后,手机会进入休眠状态(屏幕变黑),当再此按下手机的任意键后,屏幕会唤醒(屏幕变量)。这两个动作可以通过如下两个动作连接

广播动作

  • 休眠状态 Intent.ACTION_SCREEN_OFF
  • 唤醒状态 Intent.ACTION_SCREEN_ON
 private void screenOnOff() {        ScreenOnOffReceiver screenOnOffReceiver = new ScreenOnOffReceiver();        IntentFilter intentFilter = new IntentFilter();        // 设置屏幕唤醒广播的动作        intentFilter.addAction(Intent.ACTION_SCREEN_ON);        // 设置屏幕休眠广播的动作        intentFilter.addAction(Intent.ACTION_SCREEN_OFF);        // 注册        registerReceiver(screenOnOffReceiver,intentFilter);    }
package com.turing.base.activity.broadcastDemo;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;public class ScreenOnOffReceiver extends BroadcastReceiver {    public ScreenOnOffReceiver() {    }    @Override    public void onReceive(Context context, Intent intent) {        // 接收屏幕唤醒状态的广播        if (Intent.ACTION_SCREEN_ON.equals(intent.getAction())) {            Log.d("screen", "ok");        } else if (Intent.ACTION_SCREEN_OFF.equals(intent.getAction())) {            Log.d("screen", "off");        }    }}

注意事项:

屏幕唤醒和休眠的广播,只能通过代码的以动态的方式注册,如果在清单文件中配置,则不起作用。


开机自动运行

广播动作

android.intent.action.BOOT_COMPLETED

Code

package com.turing.base.activity.service;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import com.apkfuns.logutils.LogUtils;/** * 只要完成两项工作: 启动服务 和 显示一个Activity提示服务启动成功(主题设置为Dialog的形式) */public class StartupReceiver extends BroadcastReceiver {    public StartupReceiver() {    }    @Override    public void onReceive(Context context, Intent intent) {        LogUtils.e("StartupReceiver  onReceive");        // 如果是开机启动的Action        if(intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)){            // 启动Activity            Intent activityIntent = new Intent(context,BootCompletedMessageAct.class);            // 想要在Service中启动Activity,必须设置如下标志            activityIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);            context.startActivity(activityIntent);            //启动服务            Intent serviceIntent = new Intent(context,StartupService.class);            context.startService(serviceIntent);        }    }}
  <!-- 开机广播 -->        <receiver android:name=".activity.service.StartupReceiver">            <intent-filter >                <action android:name="android.intent.action.BOOT_COMPLETED" />            </intent-filter>        </receiver>

显示手机电池的当前电量

查看电池的电量也需要接收一个系统广播,本demo是通过registerReceiver方法进行注册的。

广播动作

Intent.ACTION_BATTERY_CHANGED

Code

package com.turing.base.activity.broadcastDemo;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.widget.TextView;import com.turing.base.R;public class BatteryInfoAct extends AppCompatActivity {    private TextView tv_batteryInfo;    private BroadcastReceiver batteryChangedReceiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            if (Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())) {                //level标识当前电量的值                int level = intent.getIntExtra("level", 0);                // scale标识电量的总刻度                int scale = intent.getIntExtra("scale", 100);                // 将当前电量换算成百分比的形式                tv_batteryInfo.setText("电池用量:" + (level * 100 / scale) + "%");            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_battery_info);        tv_batteryInfo = (TextView) findViewById(R.id.id_tv_battery);        // 注册广播        registerReceiver(batteryChangedReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));    }    @Override    protected void onPause() {        super.onPause();        if (batteryChangedReceiver != null) {            unregisterReceiver(batteryChangedReceiver);        }    }}

发送广播

sendBoradcast

可以通过sendBoradcast的方式发送广播
方法定义如下:

public void sendBroadcast(Intent intent)

下面的代码发送了一个广播,并添加了广播数据和category

// 指定广播动作Intent brdcstIntent= new Intent("com.turing.demo.sendbrdcst.MYBROADCAST");// 添加categorybrdcstIntent.addCategory("xxx.xxx.xxx");// 设置广播数据brdcstIntent.putExtra("name","XXXXX");// 发送广播sendBoradcast(brdcstIntent);

Code

两个工程,proj_send_broadcast, proj_custom_receiver

proj_send_broadcast

public class Main extends Activity{    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);    }    public void onClick_Send_Broadcast(View view)    {        Intent broadcastIntent = new Intent("mobile.android.ch10.MYBROADCAST");        broadcastIntent.addCategory("mobile.android.ch10.mycategory");        broadcastIntent.putExtra("name", "broadcast_data");        sendBroadcast(broadcastIntent);        Toast.makeText(this, "广播发送成功.", Toast.LENGTH_LONG).show();    }}

proj_custom_receiver

CustomReceiver

import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class CustomReceiver extends BroadcastReceiver{    @Override    public void onReceive(Context context, Intent intent)    {        if ("mobile.android.ch10.MYBROADCAST".equals(intent.getAction()))        {            String name = intent.getStringExtra("name");            Toast.makeText(context, name, Toast.LENGTH_LONG).show();        }    }}

清单文件

    <receiver android:name=".CustomReceiver">            <intent-filter>                <action android:name="mobile.android.ch10.MYBROADCAST" />                <category android:name="mobile.android.ch10.mycategory" />            </intent-filter>        </receiver>

验证广播接收器是否注册

 private void validateReceiver(String actionName) {        // 获取PackageManager        PackageManager packageManager = getPackageManager();        // 指定要查询广播的动作        Intent intent = new Intent(actionName);        // 返回已查到的广播接收器集合,如果没有符合条件的广播,List长度为0        List<ResolveInfo> resolveInfos = packageManager.queryBroadcastReceivers(intent,PackageManager.GET_INTENT_FILTERS);        // 显示查询到的广播的数量        Toast.makeText(this,"已发现" + resolveInfos.size() + "个接收去电广播的接收器" ,Toast.LENGTH_SHORT).show();        StringBuilder sb = new StringBuilder();        if(resolveInfos.size() > 0 ){            for (ResolveInfo resolveInfo : resolveInfos){                sb.append(resolveInfo.toString());            }        }        Toast.makeText(this,sb.toString() ,Toast.LENGTH_SHORT).show();    }
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