Android 判断网络是否连接的方法

小咪咪 2022-05-22 10:28 223阅读 0赞

用的编译器 Android Studio  
直接上代码

import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.net.ConnectivityManager;
    import android.net.NetworkInfo;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.widget.Toast;
    
    public class MainActivity extends AppCompatActivity { 
    
        private IntentFilter intentFilter;
        private NetworkChangeReceiver networkChangeReceiver;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            intentFilter = new IntentFilter();
            intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
            networkChangeReceiver = new NetworkChangeReceiver();
            registerReceiver(networkChangeReceiver,intentFilter); //注册广播接收器
        }
    
        @Override
        protected void onDestroy() {
            super.onDestroy();
            unregisterReceiver(networkChangeReceiver); //注销广播注销广播
        }
    
    //定义一个判断网络的广播 在网络连接或断开时，都会执行 onReceive 方法一次
        class NetworkChangeReceiver extends BroadcastReceiver {
                @Override
                public void onReceive(Context context, Intent intent) {
                    ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
                    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
                    if (networkInfo != null && networkInfo.isAvailable()) {
                        Toast.makeText(context, "网络打开",Toast.LENGTH_SHORT).show();
                    }
                    else {
                        Toast.makeText(context, "网络关闭",Toast.LENGTH_SHORT).show();
                    }
                }
        }
    }
    
    
    记得要在fest.xml增加权限
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>