#31 안드로이드 스튜디오 네트워크 상태 체크 (Broadcast Receiver) 예제 [ 홍드로이드 ]

<AndroidManifest.xml>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hongdroid.broadcastreceiverexample">
 
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
 
    <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>
    </application>
 
</manifest>

<activity_main.xml>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
 
    <TextView
        android:id="@+id/tv_state"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="홍드로이드"
        android:textSize="30sp"
        android:textColor="#536DFE"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
</androidx.constraintlayout.widget.ConstraintLayout>

<MainActivity.java>

import androidx.appcompat.app.AppCompatActivity;
 
import android.content.IntentFilter;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.widget.TextView;
 
public class MainActivity extends AppCompatActivity {
 
    public static TextView tv_state;
    private NetworkReceiver receiver;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        tv_state = findViewById(R.id.tv_state);
 
        // 브로드 캐스트 리시버 등록 !
        IntentFilter filter = new IntentFilter();
        receiver = new NetworkReceiver();
        filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
        registerReceiver(receiver, filter);
    }
 
 
    @Override
    protected void onDestroy() {
        super.onDestroy();
 
        // 브로드 캐스트 리시버 해제 !
        unregisterReceiver(receiver);
 
    }
}