Android的广播接收器

android的四大组件：

​ Activity、Service、BroadCast(广播)、ContentProvider

 

### BroadCast Receiver

- 四大组件之一，必须在清单（androidManifest.xml）文件中进行注册
- 是在组件之间传播数据（Intent）的一种机制
- APP哪块用到了广播？
- 电话
- 短信
- 电量
- WIFI是否连接

 

Android中出现的第一个错误？

​ 在组件中进行耗时操作，就会报application no response (ANR)

广播接收者一种有几种？

​ 标准广播

​ 动态注册 使用java代码注册

​ 静态注册 直接在androidManifest.xml注册

​ 有序广播

 

实现简单的静态注册

1. 创建广播接收者

2. 在AndroidManifest.xml中对广播接收者进行注册

3. 发送广播

实现简单的动态注册

 

 

 

 静态：

public class MainActivity7 extends AppCompatActivity {
    private Button btn_gb;
    private Button btn_dt;
   private MyDyminicReceiver myDyminicReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main7);

       btn_gb = findViewById(R.id.btn_gb);
       btn_gb.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               //发送广播给静态广播接受者
               Intent intent = new Intent();
               intent.setPackage(getPackageName());
               intent.setAction("houpu");
               intent.putExtra("info","你好啊");
               sendBroadcast(intent);

           }
       });

public class MainActivity8 extends AppCompatActivity {
   private MyNetWorkReceiver myNetWorkReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main8);
        //注册
        myNetWorkReceiver = new MyNetWorkReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(myNetWorkReceiver,intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //反注册
        unregisterReceiver(myNetWorkReceiver);
    }

    class MyNetWorkReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            //接收到系统给提供的广播
            ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();//报错因为权限
            if (networkInfo != null && networkInfo.isAvailable()){
                if (networkInfo.getType() == ConnectivityManager.TYPE_WIFI){
                    Toast.makeText(context,"WLFI",Toast.LENGTH_SHORT).show();
                }else if (networkInfo.getType()==ConnectivityManager.TYPE_MOBILE){
                    Toast.makeText(context,"流量",Toast.LENGTH_SHORT).show();
                }
            }else {
                Toast.makeText(context,"网络未连接",Toast.LENGTH_SHORT).show();
            }
        }
    }
}

动态：

 btn_dt = findViewById(R.id.btn_dt);
   btn_dt.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
        Intent intent = new Intent();
        intent.setAction("houpu1");
        intent.putExtra("info","动态你好你好");
        sendBroadcast(intent);
       }
   });
    //注册动态广播接收者
    myDyminicReceiver  = new MyDyminicReceiver();
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction("houpu1");
    registerReceiver(myDyminicReceiver,intentFilter);
}
class MyDyminicReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.i("动态广播接收者",intent.getStringExtra("info"));
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
    unregisterReceiver(myDyminicReceiver);
}