Android判断联网状态，Wifi信号强度，注册网络变化广播事件

code

package com.idogfooding.lawsonsot.common;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;

import com.idogfooding.lawsonsot.model.WifiResultInfo;
/**
 * 
 * */
public class WiFiUtil {
    /**
     * 判断是否联网
     */
    public static boolean checkConnectNetwork(Context context) {
        ConnectivityManager conn = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo net = conn.getActiveNetworkInfo();
        if (net != null && net.isConnected()) {
            return true;
        }
        return false;
    }

    /**
     * 获取已连接的wifi
     */
    public static WifiResultInfo getConnectedWifi(Context context) {
//        Context context = SysApplication.getContext();
        WifiResultInfo wifiResultInfo = null;
        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();

        if (wifiInfo != null) {
            wifiResultInfo = new WifiResultInfo();
            //名称
            String ssid = wifiInfo.getSSID();
            //信号强度，得到的值是一个0到-100的区间值，是一个int型数据
            int rssi = wifiInfo.getRssi();

            if(ssid.startsWith("\"") && ssid.endsWith("\""))
            {
                ssid = ssid.substring(1, ssid.length() - 1);
            }
            //信号强度等级，根据强度值，分为6个等级，5最大，表示强度最高，0表示没连Wifi。
            int level = WifiManager.calculateSignalLevel(rssi, 6);
            String supplicantState = wifiInfo.getSupplicantState().toString();

            wifiResultInfo.setWifiLevel(level);
            wifiResultInfo.setRssi(rssi);
            wifiResultInfo.setSsid(ssid);
            wifiResultInfo.setSupplicantState(supplicantState);
        }
        return wifiResultInfo;
    }
}

 AndroidManifest.xml

<!-- 联网，网络状态 -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <!-- WIFI改变，WIFI状态 -->
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <!-- 申请定位权限 否则的话，wifiManager.getScanResults()获取不到任何的数据 -->
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

注册网络变化接收通知

/**
     * 注册网络变化接收通知
     * */
    public static void regNetChageRecever(Context context){
        NetChangeReceiver receiver = new NetChangeReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        context.registerReceiver(receiver, intentFilter);
    }

Recever

package com.jay.common;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

/**
 * 接收 网络状态变化 发出的通知
 * */
public class NetChangeReceiver extends BroadcastReceiver {

    @SuppressLint("UnsafeProtectedBroadcastReceiver")
    @Override
    public void onReceive(Context context, Intent intent) {
        try {
            ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            if (networkInfo != null && networkInfo.isConnected()) {
                //有网
                String res = "";
                Activity activity = BaseForm.curActivity();
                activity.runOnUiThread(()->{
//                    activity.findViewById(R.id.txtDes);
                });
            } else {
                //无网
            }
        } catch (Exception e) {
            //ignore
        }
    }
}

来源：https://blog.csdn.net/chongchi_wxcc/article/details/126941037