1、BroadcastReceiver基礎

• 動態註冊
• 靜態註冊
• 動態繫結
• 動態登出
• 實現靜態登出【其實就是設定不去響應，並沒有所謂登出】

2、程式碼走起

MyBroadcast：

會在MianActivity中使用程式碼動態註冊它

package weizhengzhou.top.interviewbroadcast.BroadcastDemo;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

/**
 * Created by 75213 on 2017/7/11.
 * Are you known Broadcast ?
 * Broadcast（廣播）是在在元件中傳播資料（Intent）的一種機制。通過Broadcast傳送者和接受者都不需要知道對方是否存在。
 * Are you known BroadcastReceiver ?
 * BroadcastReceiver是對傳送出來的廣播進行過濾接收並響應的一類元件。
 */
 


// 使用動態註冊
public class MyBroadcast extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context , "動態註冊廣播" , Toast.LENGTH_SHORT).show();
    }
}

MyBroadcast2：

會在AndroidManifes.xml中使用j靜態註冊它

package weizhengzhou.top.interviewbroadcast.BroadcastDemo;

import
 
 android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

/**
 * Created by 75213 on 2017/7/11.
 */

//使用靜態註冊
public class MyBroadcast2 extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context , "靜態註冊廣播"
 
 , Toast.LENGTH_SHORT).show();
    }
}

MianActivity:

裡面有部分程式碼是實現藍芽狀態監聽的

package weizhengzhou.top.interviewbroadcast;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.ComponentName;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import weizhengzhou.top.interviewbroadcast.BluetoothStateBroadcastReceiver.BluetoothStateBroadcastReceiver;
import weizhengzhou.top.interviewbroadcast.BroadcastDemo.MyBroadcast;
import weizhengzhou.top.interviewbroadcast.BroadcastDemo.MyBroadcast2;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private Button mButton1 , mButton2 , mButton3 , mButton4 , mButton5 , mButton6;
    private MyBroadcast mMyBroadcast;
    private BluetoothStateBroadcastReceiver mReceiver;
    private BluetoothAdapter mBluetoothAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMyBroadcast = new MyBroadcast();
        mReceiver = new BluetoothStateBroadcastReceiver();
        mButton1 = (Button)findViewById(R.id.testButton1);
        mButton2 = (Button)findViewById(R.id.testButton2);
        mButton3 = (Button)findViewById(R.id.testButton3);
        mButton4 = (Button)findViewById(R.id.testButton4);
        mButton5 = (Button)findViewById(R.id.testButton5);
        mButton6 = (Button)findViewById(R.id.testButton6);
        mButton1.setOnClickListener(this);
        mButton2.setOnClickListener(this);
        mButton3.setOnClickListener(this);
        mButton4.setOnClickListener(this);
        mButton5.setOnClickListener(this);
        mButton6.setOnClickListener(this);
        registerReceiver(mReceiver , makeFilters());
        //獲取藍芽介面卡例項。如果裝置不支援藍芽則返回null
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        //獲取狀態碼
       int test =  mBluetoothAdapter.getState();
        //判斷藍芽狀態
        switch (test){
            case BluetoothAdapter.STATE_CONNECTED:
                Toast.makeText(this , "判斷狀態為連線中" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothAdapter.STATE_CONNECTING:
                Toast.makeText(this , "判斷狀態為連線" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothAdapter.STATE_DISCONNECTED:
                Toast.makeText(this , "判斷狀態為斷開" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothAdapter.STATE_DISCONNECTING:
                Toast.makeText(this , "判斷狀態為斷中" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothAdapter.STATE_OFF:
                Toast.makeText(this , "關閉" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothAdapter.STATE_ON:
                Toast.makeText(this , "開啟" , Toast.LENGTH_SHORT).show();
                break;
            default:
                break;
        }
    }

    //藍芽監聽需要新增的Action
    private IntentFilter makeFilters(){
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("android.bluetooth.a2dp.profile.action.CONNECTION_STATE_CHANGED");
        intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        intentFilter.addAction(BluetoothDevice.ACTION_ACL_CONNECTED);
        intentFilter.addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED);
        intentFilter.addAction("android.bluetooth.BluetoothAdapter.STATE_OFF");
        intentFilter.addAction("android.bluetooth.BluetoothAdapter.STATE_ON");
        return intentFilter;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.testButton1:
                //動態註冊
                IntentFilter intentFilter = new IntentFilter();
                intentFilter.addAction("weizhengzhou.top");
                registerReceiver(mMyBroadcast, intentFilter);
                break;
            case R.id.testButton2:
                //傳送動態註冊的廣播資訊
                Intent intent = new Intent("weizhengzhou.top");
                sendBroadcast(intent);
                break;
            case R.id.testButton3:
                //傳送靜態註冊的廣播資訊
                Intent intent2 = new Intent("weizhengzhou.top.test");
                sendBroadcast(intent2);
                break;
            case R.id.testButton4:
                //解除動態繫結的廣播接收者
                unregisterReceiver(mMyBroadcast);
                break;
            case R.id.testButton5:
                //實現不響應靜態註冊的廣播
                getPackageManager().setComponentEnabledSetting(
                        new ComponentName("weizhengzhou.top.interviewbroadcast" ,
                                MyBroadcast2.class.getName()),
                        PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                        PackageManager.DONT_KILL_APP);
                break;
            case R.id.testButton6:
                //重新啟用靜態廣播接收者
                getPackageManager().setComponentEnabledSetting(
                        new ComponentName("weizhengzhou.top.interviewbroadcast",
                                MyBroadcast2.class.getName()),
                                PackageManager.COMPONENT_ENABLED_STATE_DEFAULT,
                                PackageManager.DONT_KILL_APP);
                break;
        }
    }
}

3、藍芽狀態監聽具體程式碼

BluetoothStateBroadcastReceiver:

主要實現藍芽狀態廣播接收

package weizhengzhou.top.interviewbroadcast.BluetoothStateBroadcastReceiver;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

/**
 * Created by 75213 on 2017/7/11.
 * 實現藍芽狀態廣播接收
 */

public class BluetoothStateBroadcastReceiver extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        //獲取藍芽裝置例項【如果無裝置連結會返回null，如果在無例項的狀態下呼叫了例項的方法，會報空指標異常】
        //主要與藍芽裝置有關係
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        Toast.makeText(context , "監聽藍芽變化" , Toast.LENGTH_SHORT).show();
        switch (action){
            case BluetoothDevice.ACTION_ACL_CONNECTED:
                Toast.makeText(context , "藍芽裝置:" + device.getName() + "已連結" , Toast.LENGTH_SHORT).show();
                break;
            case BluetoothDevice.ACTION_ACL_DISCONNECTED:
                Toast.makeText(context , "藍芽裝置:" + device.getName() + "斷開連結" , Toast.LENGTH_SHORT).show();
                break;
            //上面的兩個連結監聽，其實也可以BluetoothAdapter實現，修改狀態碼即可
            case BluetoothAdapter.ACTION_STATE_CHANGED:
                int blueState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
                switch (blueState){
                    case BluetoothAdapter.STATE_OFF:
                        Toast.makeText(context , "藍芽關閉", Toast.LENGTH_SHORT).show();
                        break;
                    case BluetoothAdapter.STATE_ON:
                        Toast.makeText(context , "藍芽開啟"  , Toast.LENGTH_SHORT).show();
                        break;
                }
                break;
            default:
                break;
        }

    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="weizhengzhou.top.interviewbroadcast">

    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED"/>
    <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">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <receiver android:name=".BroadcastDemo.MyBroadcast2"
                  android:enabled="true"
                  android:exported="true">
            <intent-filter>
                <action android:name="weizhengzhou.top.test"></action>
            </intent-filter>
        </receiver>
    </application>

</manifest>