Android利用WiFiManager扫描AP列表的实例

1. 简述
WiFi是Android手机重要功能，在设计过程中需要经常测试和比较WiFi信号、扫描到AP个数等。本实例利用Android框架的WiFiManager对象扫描AP列表，每个AP的信息包括SSID、BSSID、加密方式、信号等级、频率、带宽、时间戳等。说明一下，Android系统定义了带宽常数CHANNNEL_WIDTH_20MHZ=0; CHANNNEL_WIDTH_40MHZ=1;CHANNNEL_WIDTH_80MHZ=2;CHANNNEL_WIDTH_160MHZ=3;CHANNNEL_WIDTH_80MHZ_PLUS_MHZ=4，在扫描结果中用常数表示带宽。本实例有3个部分，UI线程主要设置用户界面显示AP列表、翻页处理、初始化SimpleAdapter、获得WiFiManager对象、开始扫描线程、注册广播接收器；定时扫描线程只负责扫描；广播接收器BroadcastReceiver mWifiStateReceiver，处理扫描返回数据，并在用户界面空闲时更新数据。程序源码如下:WiFi是Android手机重要功能，在设计过程中需要经常测试和比较WiFi信号、扫描到AP个数等。本实例利用Android框架的WiFiManager对象扫描AP列表，每个AP的信息包括SSID、BSSID、加密方式、信号等级、频率、带宽、时间戳等。说明一下，Android系统定义了带宽常数CHANNNEL_WIDTH_20MHZ=0; CHANNNEL_WIDTH_40MHZ=1;CHANNNEL_WIDTH_80MHZ=2;CHANNNEL_WIDTH_160MHZ=3;CHANNNEL_WIDTH_80MHZ_PLUS_MHZ=4，在扫描结果中用常数表示带宽。本实例有3个部分，UI线程主要设置用户界面显示AP列表、翻页处理、初始化SimpleAdapter、获得WiFiManager对象、开始扫描线程、注册广播接收器；定时扫描线程只负责扫描；广播接收器BroadcastReceiver mWifiStateReceiver，处理扫描返回数据，并在用户界面空闲时更新数据。程序源码如下:
2. WiFiAdmin.java

//列出手机扫描的WiFi AP,1秒更新一次。
package com.lmy.wifiadmin;

import android.Manifest;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.AbsListView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import static java.lang.Thread.sleep;

public class WiFiAdmin extends AppCompatActivity {
    //定义WifiManager对象
    private WifiManager mWifiManager;
    private final static int REQUEST_LOCATION=100;
    private ListView lvWifiList;
    private TextView mytxv;
    private SimpleAdapter myadapter;
    private ArrayList> data=new ArrayList>();
    private int position;
    private int myscrollstate=AbsListView.OnScrollListener.SCROLL_STATE_IDLE;
    private IntentFilter mWifiStateFilter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        verifyCoarseLocationPermissions(WiFiAdmin.this);
        verifyFineLocationPermissions(WiFiAdmin.this);
        lvWifiList = (ListView) findViewById(R.id.lv);
        lvWifiList.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                myscrollstate = scrollState;
                if(scrollState==AbsListView.OnScrollListener.SCROLL_STATE_IDLE){
                    position = view.getFirstVisiblePosition();
                }
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

            }

        });

    myadapter = new SimpleAdapter(WiFiAdmin.this, data, R.layout.oneline, new String[]{"no", "ap"}, new int[]{R.id.txvno, R.id.txvap});
    mytxv=findViewById(R.id.txv);
    mWifiManager = (WifiManager)getApplicationContext().getSystemService(Context.WIFI_SERVICE);
    if(mWifiManager==null) return;

    if(!mWifiManager.isWifiEnabled()){
        mWifiManager.setWifiEnabled(true);
    }
    mWifiStateFilter = new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);

    registerReceiver(mWifiStateReceiver, mWifiStateFilter);

    new Thread(new Runnable() {
        @Override
        public void run() {
            while(true){
                mWifiManager.startScan();
                try {
                    sleep(1000);
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        }
    }).start();
}

private final BroadcastReceiver mWifiStateReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
         if (intent.getAction().equals(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
            handleScanResultsAvailable();
        } else {
            Log.e("WiFi", "Received an unknown Wifi Intent");
        }
    }
};

private void handleScanResultsAvailable() {
    int i;
    List mWifiList = mWifiManager.getScanResults();

    if(mWifiList!=null) {
        if (myscrollstate == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
        data.clear();
        for (i = 0; i < mWifiList.size(); i++) {
            HashMap map = new HashMap();
            map.put("no", Integer.toString(i + 1));
            map.put("ap", mWifiList.get(i).toString());
            data.add(map);
        }
        mytxv.setText("Total AP:" + Integer.toString(mWifiList.size()));

            lvWifiList.setAdapter(myadapter);
            if (position < mWifiList.size()) lvWifiList.setSelection(position);
        }
    }
}
private void verifyCoarseLocationPermissions(Activity activity){
    int permissionLocation = ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION);
    if (permissionLocation != PackageManager.PERMISSION_GRANTED )  {
        ActivityCompat.requestPermissions(activity,new String[]{Manifest.permission.ACCESS_COARSE_LOCATION} ,REQUEST_LOCATION);
    }
}

private void verifyFineLocationPermissions(Activity activity){
    int permissionLocation = ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION);
    if (permissionLocation != PackageManager.PERMISSION_GRANTED )  {
        ActivityCompat.requestPermissions(activity,new String[]{Manifest.permission.ACCESS_FINE_LOCATION} ,REQUEST_LOCATION);
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode){
        case REQUEST_LOCATION:
            if ((grantResults.length>0)&&(grantResults[0]==PackageManager.PERMISSION_GRANTED)){
                Toast.makeText(getApplicationContext(),permissions[0]+"权限申请成功",Toast.LENGTH_LONG).show();
            }else{
                Toast.makeText(getApplicationContext(),permissions[0]+"权限申请失败",Toast.LENGTH_LONG).show();
            }
            break;
    }
}

}

3. main.xml

4.oneline.xml

5. AndroidManifest.xml