[组件_BroadcastReceiver] 广播用法 #Android

广播_动态注册.md

MainActivity.java

    
    private IntentFilter intentFilter;
    private NetworkChangeReceiver networkChangeReceiver; // 内部类
    
    onCreate {
        intentFilter = new IntentFilter();
        // 添加 Action
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE"); 

        networkChangeReceiver = new NetworkChangeReceiver(); // 内部类实例
        registerReceiver(networkChangeReceiver, intentFilter);
    }
    
    // 内部类
    class NetworkChangeReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {

            // 获得系统服务类
            ConnectivityManager connectivityManager = (ConnectivityManager)
                    getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();

            // 具体的使用场景
            if (networkInfo != null && networkInfo.isAvailable()) {
                Toast.makeText(context, "network is available", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(context, "network is unavailable", Toast.LENGTH_SHORT).show();
            }

        }
    }
    
    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy");
        unregisterReceiver(networkChangeReceiver);
    }
}
    

AndroidManifest.xml

添加权限

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

广播_自定义广播_标准广播.md

应用场景

点击 Mainactivity 的 Button ,发送广播 然后 App 接收到并弹出 Toast

Mainactivity.java

        // Example 3 MY_BROADCAST
        Button button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent("com.iyounix.android.a010broadcasts.MY_BROADCAST");
                sendBroadcast(intent);
            }
        });

MyBroadcastReceiver.java

public class MyBroadcastReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    Toast.makeText(context, "received in Younix BoardcastReceiver",Toast.LENGTH_SHORT).show();
}

}

AndroidManifest.xml

        <receiver android:name=".MyBroadcastReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.iyounix.android.a010broadcasts.MY_BROADCAST"/>
            </intent-filter>
        </receiver>

广播_静态注册.md

应用场景

接受开机广播 右击 包名 -> New -> Other -> BroadcastReceiver enabled = true 表示是否启用该 BoardcastReceiver exported = ture 表示允许接受本程序以外的 Boardcast

BootCompleteReceiver.java

public class BootCompleteReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
//        throw new UnsupportedOperationException("Not yet implemented");
        Toast.makeText(context, "Boot Complete", Toast.LENGTH_SHORT).show();
    }
}

AndroidManifest.xml

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

    <application
        <receiver
            android:name=".BootCompleteReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
            </intent-filter>
        </receiver>
    </application>