判断网络是否链接

import android.content.Context;import android.net.ConnectivityManager;import android.net.NetworkInfo;/** * Created by lenovo on 2017/12/19. *///网络状态判断工具类（外部类）public class PanDuanUtils {    public static boolean isNetWork(Context context){        if (context != null){            ConnectivityManager manager= (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);            NetworkInfo info = manager.getActiveNetworkInfo();            if (info != null){                return info.isAvailable();            }        }        return false;    }}

//主方法内写

//当应用打开时，判断网络是否可用boolean work = isNetWork(this);if (work == true){    //网络正常时弹出吐司，提示网络正常    Toast.makeText(this,"网络已连接！！！",Toast.LENGTH_LONG).show();}else {    //不可用时弹出对话框提示用户进入设置页面    Toast.makeText(this,"网络未连接！！！",Toast.LENGTH_LONG).show();    //跳转到设置页面    startActivity(new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS));}

需要配置的权限：uses-permission android:name=”android.permission.ACCESS_NETWORK_STATE”