app内实现搜索wifi和连接wifi

权限：

<uses-permission android:name="android.permission.NETWORK_SETTINGS"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.LOCAL_MAC_ADDRESS" />

核心api：

WifiManager mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);

// 打开WIFI
public void openWifi() {
    if (!mWifiManager.isWifiEnabled()) {
        mWifiManager.setWifiEnabled(true);
    }
}

//搜索wifi
private void getNearbyWifi(){
    openWifi();
    wifiAdmin.startScan();
}

//获取搜索到的wifi结果,扫描到wifi，系统会发出广播，定义一个recever并在其中拿到扫描结果

IntentFilter filter = new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
registerReceiver(mWifiScanReceiver, filter); // 注册WiFi扫描的广播接收器mWifiManager.getScanResults();

连接wifi，这里有个坑，需要吧targetSDKVersion定位28。目前对于高于28的target，我无法实现自动连接wifi。下面是wpa/wpa2的密码加密方式，其它的wifi密码加密方式由于被淘汰很久了，我没有copy。

public WifiConfiguration CreateWifiInfo(String SSID, String Password) {
    WifiConfiguration config = new WifiConfiguration();
    config.allowedAuthAlgorithms.clear();
    config.allowedGroupCiphers.clear();
    config.allowedKeyManagement.clear();
    config.allowedPairwiseCiphers.clear();
    config.allowedProtocols.clear();
    config.SSID = "\"" + SSID + "\"";

    WifiConfiguration tempConfig = this.IsExsits(SSID);
    if (tempConfig != null) {
        mWifiManager.removeNetwork(tempConfig.networkId);
    }
    config.preSharedKey = "\"" + Password + "\"";
    config.hiddenSSID = true;
    config.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
    config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
    config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
    config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
    //config.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
    config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
    config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
    config.status = WifiConfiguration.Status.ENABLED;

    return config;
}

// 添加一个网络并连接
public void addNetwork(WifiConfiguration wcg) {
    int wcgID = mWifiManager.addNetwork(wcg);
    boolean b = mWifiManager.enableNetwork(wcgID, true);
    System.out.println("a----" + wcgID);
    System.out.println("b----" + b);
    boolean r = mWifiManager.reconnect();
    System.out.println("r----" + r);
}