这是我的广播接收器类。我正在尝试制作一个wifi扫描仪应用程序。在我的应用程序中，我将在回收视图中显示所有可用的wifi，并使用密码连接到任何网络，然后忘记网络，并在android studio中查看所有已连接网络的信息：

package com.example.mywificonnect;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pManager;
import android.util.Log;
import android.widget.Toast;

import java.util.List;

public class WifiScanner extends BroadcastReceiver {

    private static final String TAG = "WiFiScanReceiver";
    MainActivity mainActivity;
//    ScanResult scanResult;
    WifiManager wifiManagerer;

    public WifiScanner(MainActivity mainActivity) {
//        super();
        this.mainActivity = mainActivity;
    }

    @Override
    public void onReceive(Context context, Intent intent) {

       /* String action = intent.getAction();
        if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action))*/
//        wifiManager = (WifiManager) mainActivity.getApplicationContext().getSystemService(Context.WIFI_SERVICE);

        List<ScanResultresults = mainActivity.wifiManager.getScanResults();
//        int size=results.size();
        /*for (ScanResult result: results){
            Toast.makeText(mainActivity,result.SSID+""+result.level,Toast.LENGTH_SHORT).show();
        }*/
        ScanResult bestSignal = null;
        for (ScanResult scanResult : results) {
            if (bestSignal == null
                    || WifiManager.compareSignalLevel(bestSignal.level, scanResult.level) < 0)
                bestSignal = scanResult;
        }

        String message = String.format("%s networks found. %s is the strongest.",
                results.size(), bestSignal.SSID);

        Toast.makeText(mainActivity,message,Toast.LENGTH_LONG).show();
//        if (size==0){
//            Toast.makeText(mainActivity,"Size Khali Hai",Toast.LENGTH_LONG).show();
//        }
        /*else {
            Toast.makeText(mainActivity, size, Toast.LENGTH_LONG).show();
        }*/
        Log.d(TAG, "onReceive message: " + message);
    }
}

这是我的主要活动代码。显示所有wifi列表，然后在recyclerview中显示列表。

package com.example.mywificonnect;

import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String TAG = "WiFiDemo";
    public WifiManager wifiManager;
    public BroadcastReceiver broadcastReceiver;

    private TextView tvStatus;
    private Button btnScan;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tvStatus = findViewById(R.id.tvStatus);
        btnScan = findViewById(R.id.btnScan);
        btnScan.setOnClickListener(this);

        setLocationPermission();
        setWifiStatus();
    }

    private void setWifiStatus() {
        wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

        WifiInfo info = wifiManager.getConnectionInfo();
        tvStatus.append("\n\nWifi Status: " + info.toString());
        List<WifiConfigurationconfigurations = wifiManager.getConfiguredNetworks();
        for (WifiConfiguration wifiConfiguration : configurations) {
            tvStatus.append("\n\n" + wifiConfiguration.toString());
        }
        if (broadcastReceiver == null)
            broadcastReceiver = new WifiScanner(this);
        registerReceiver(broadcastReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
        Log.d(TAG, "onCreate()");

    }

    private void setLocationPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) !=
PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1001);
        }
    }

    @Override
    protected void onStop() {
        super.onStop();
        unregisterReceiver(broadcastReceiver);
    }

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(broadcastReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    }

    @Override
    public void onClick(View v) {
        Toast.makeText(this, "On Click Clicked. Toast to That!!!", Toast.LENGTH_LONG).show();

        if (v.getId() == R.id.btnScan) {
            Log.d(TAG, "onClick() wifi.startScan()");
            wifiManager.startScan();
        }
    }
  }