Wifi列表扫描和Wifi链接

 上面的截图，就是本文要介绍的主要功能。

 1.准备工作，声明权限：

 <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.WRITE_SETTINGS"
        tools:ignore="ProtectedPermissions" />

2.打开WIfi：

    1）申请权限：注意的一点就是，打开wifi需要申请位置权限

    String[] permsLocation = {"android.permission.ACCESS_WIFI_STATE"
            , "android.permission.CHANGE_WIFI_STATE"
            , "android.permission.ACCESS_COARSE_LOCATION"
            , "android.permission.ACCESS_FINE_LOCATION"};

    //获取权限
    private void getPerMission() {
        mPermissionsChecker = new PermissionsChecker(MainActivity.this);
        if (mPermissionsChecker.lacksPermissions(permsLocation)) {
            ActivityCompat.requestPermissions(MainActivity.this, permsLocation, 1000);
        }
    }

  2）打开wifi

     获取WifiManager：

 wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

  public boolean openWifi(WifiManager mWifiManager) {
        boolean bRet = true;
        Log.e("nyz", "wifi enable " + mWifiManager.isWifiEnabled());
        //android Q 不能使用，只能跳转设置界面，手动开启。startActivity(Intent(Settings.ACTION_WIFI_SETTINGS))
        if (!mWifiManager.isWifiEnabled()) {
            bRet = mWifiManager.setWifiEnabled(true);
        }
        Log.e("nyz", "wifi result " + bRet);
        return bRet;
    }

  需要注意的一点就是，Android10以上下面的打开Wifi的功能将会失效，需要跳转到设置界面，由用户手动打开。

 * @deprecated Starting with Build.VERSION_CODES#Q, applications are not allowed to
     * enable/disable Wi-Fi.
     * Compatibility Note: For applications targeting
     * {@link android.os.Build.VERSION_CODES#Q} or above, this API will always return {@code false}
     * and will have no effect. If apps are targeting an older SDK (
     * {@link android.os.Build.VERSION_CODES#P} or below), they can continue to use this API.
     */
    @Deprecated
    public boolean setWifiEnabled(boolean enabled) {
        try {
            return mService.setWifiEnabled(mContext.getOpPackageName(), enabled);
        } catch (RemoteException e) {
            throw e.rethrowFromSystemServer();
        }
    }

3.获取WIfi列表：

    1）创建一个BroadCastReceiver：

       收到 WifiManager.SCAN_RESULTS_AVAILABLE_ACTION 广播后，可以获取WIfi列表

 
   class WifiReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (TextUtils.isEmpty(intent.getAction())) {
                return;
            }
            String action = intent.getAction();
            Log.e("nyz", "action " + action);
 
 
            if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action)) {
                boolean result = intent.getBooleanExtra(WifiManager.EXTRA_RESULTS_UPDATED, false);
                List<ScanResult> wifiList = wifiManager.getScanResults();
                Log.e("nyz", "results " + wifiList.size() + " result " + result);
                if (wifiList != null) {
                    for (int i = 0; i < wifiList.size(); i++) {
                        ScanResult wifi = wifiList.get(i);
                        if (TextUtils.isEmpty(wifi.SSID)) {
                            continue;
                        }
                        Log.e("nyz", "BSSID " + wifi.BSSID);
                        Log.e("nyz", "SSID " + wifi.SSID);
                        Log.e("nyz", "level " + wifi.level);
                        Log.e("nyz", "capabilities " + wifi.capabilities);
                        //拿到结果后，可以更新界面，在界面展示
                    }
                }
            } else if (WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION.equals(action)) {
 
            } else if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
 
            }
 
        }
    }

  2）注册和反注册：

 private void registerReceiver() {
        wifiReceiver = new WifiReceiver();
        IntentFilter filter = new IntentFilter();
        filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        filter.addAction(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION);
        registerReceiver(wifiReceiver, filter);
 
    }
 
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(wifiReceiver);
    }

  3）开始扫描Wifi：

      调用  wifiManager.startScan();开始扫描。搜索到附近的Wifi后，系统会发布广播，可以在广播接收者中，收到wifi列表信息。

 findViewById(R.id.scan).setOnClickListener(v -> {
 
 
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(MainActivity.this, permsLocation, 1000);
                return;
            }
            boolean result = wifiManager.startScan();
            Log.e("nyz", "result " + result);
            List<ScanResult> wifiList = wifiManager.getScanResults();
            Log.e("nyz", "size " + wifiList.size());
//            if (wifiList != null) {
//                for (int i = 0; i < wifiList.size(); i++) {
//                    ScanResult wifi = wifiList.get(i);
//                    Log.e("nyz", "BSSID " + wifi.BSSID);
//                    Log.e("nyz", "SSID " + wifi.SSID);
//                    Log.e("nyz", "level " + wifi.level);
//                    Log.e("nyz", "capabilities " + wifi.capabilities);
//                }
//            }
            WifiInfo wifiInfo = wifiManager.getConnectionInfo();
            Log.e("nyz", "wifiInfo = " + (wifiInfo == null));
 
 
        });

4.链接wifi：   

 private void connWifi(Context context, String ssid, String pwd) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        Log.e("nyz", "sdk " + Build.VERSION.SDK_INT);
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
            WifiConfiguration config = createWifiInfo(ssid, pwd);
            int netId = wifiManager.addNetwork(config);
            Log.e("nyz", "netID " + netId);
            boolean isConn = wifiManager.enableNetwork(netId, true);
            Log.e("nyz", "isConn " + isConn);
        } else {
//            connectSuggestion(ssid, pwd);
            connectSpecifier(ssid, pwd);
 
        }
 
    }

          在Android10以前，可以通过addNetwork的方式进行链接，在Android10以后，这种方式就不推荐使用了。

  * @deprecated
     * a) See {@link WifiNetworkSpecifier.Builder#build()} for new
     * mechanism to trigger connection to a Wi-Fi network.
     * b) See {@link #addNetworkSuggestions(List)},
     * {@link #removeNetworkSuggestions(List)} for new API to add Wi-Fi networks for consideration
     * when auto-connecting to wifi.
     * <b>Compatibility Note:b> For applications targeting
     * {@link android.os.Build.VERSION_CODES#Q} or above, this API will always return {@code -1}.
     */
    @Deprecated
    public int addNetwork(WifiConfiguration config) {
        if (config == null) {
            return -1;
        }
        config.networkId = -1;
        return addOrUpdateNetwork(config);
    }

  Android10以后链接wifi：

    1)建议的方式：

     官方文档：适用于互联网连接的 WLAN 建议 API  |  Android 开发者  |  Android Developers

 @RequiresApi(api = Build.VERSION_CODES.Q)
    private void connectSuggestion(String ssid, String pwd) {
        WifiNetworkSuggestion suggestion2 =
                new WifiNetworkSuggestion.Builder()
                        .setSsid(ssid)
                        .setWpa2Passphrase(pwd)
                        //是否可以接收到android.net.wifi.action.WIFI_NETWORK_SUGGESTION_POST_CONNECTION
                        .setIsAppInteractionRequired(true)
                        .build();
        List<WifiNetworkSuggestion> suggestionsList = new ArrayList<WifiNetworkSuggestion>();
        suggestionsList.add(suggestion2);
 
        int status = wifiManager.addNetworkSuggestions(suggestionsList);
        Log.e("nyz", "status " + status);
        if (status != WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS) {
 
        }
    }

   2）点对点的方式：

官方文档：WifiNetworkSpecifier  |  Android Developers

  @RequiresApi(api = Build.VERSION_CODES.Q)
    private void connectSpecifier(String ssid, String pwd) {
        WifiNetworkSpecifier specifier = new WifiNetworkSpecifier.Builder()
                .setSsidPattern(new PatternMatcher(ssid, PatternMatcher.PATTERN_PREFIX))
                .setWpa2Passphrase(pwd).build();
 
        NetworkRequest request = new NetworkRequest.Builder()
                .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
                .setNetworkSpecifier(specifier)
                .build();
        ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
 
        manager.requestNetwork(request, new ConnectivityManager.NetworkCallback() {
            @Override
            public void onAvailable(@NonNull Network network) {
                super.onAvailable(network);
                Log.e("nyz", "onAvailable");
                if (network != null) {
                }
 
            }
 
            @Override
            public void onUnavailable() {
                super.onUnavailable();
                Log.e("nyz", "onUnavailable");
            }
 
            @Override
            public void onCapabilitiesChanged(@NonNull Network network, @NonNull NetworkCapabilities networkCapabilities) {
                super.onCapabilitiesChanged(network, networkCapabilities);
                Log.e("nyz", "网络变化");
            }
        });
 
    }