我也试着连接到网络。 以上提出的解决方案都不适用于hugerock t70。 wifiManager.disconnect()函数;不断开当前网络。 Аnd因此不能重新连接到指定的网络。 我修改了上面的代码。 对我来说，代码bolow工作完美:

String networkSSID = "test";
String networkPass = "pass";

WifiConfiguration conf = new WifiConfiguration();
conf.SSID = "\"" + networkSSID + "\"";   
conf.wepKeys[0] = "\"" + networkPass + "\""; 
conf.wepTxKeyIndex = 0;
conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40); 
conf.preSharedKey = "\""+ networkPass +"\"";

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

int networkId = wifiManager.addNetwork(conf);
wifi_inf = wifiManager.getConnectionInfo();

/////important!!!
wifiManager.disableNetwork(wifi_inf.getNetworkId());
/////////////////

wifiManager.enableNetwork(networkId, true);

如果你的设备知道Wifi配置(已经存储)，我们可以跳过火箭科学。只需循环配置，检查SSID是否匹配。如果是，连接并返回。

设置权限:

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

连接:

    try {
    String ssid = null;
    if (wifi == Wifi.PCAN_WIRELESS_GATEWAY) {
        ssid = AesPrefs.get(AesConst.PCAN_WIRELESS_SSID,
                context.getString(R.string.pcan_wireless_ssid_default));
    } else if (wifi == Wifi.KJ_WIFI) {
        ssid = context.getString(R.string.remote_wifi_ssid_default);
    }

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

    List<WifiConfiguration> wifiConfigurations = wifiManager.getConfiguredNetworks();

    for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
        if (wifiConfiguration.SSID.equals("\"" + ssid + "\"")) {
            wifiManager.enableNetwork(wifiConfiguration.networkId, true);
            Log.i(TAG, "connectToWifi: will enable " + wifiConfiguration.SSID);
            wifiManager.reconnect();
            return null; // return! (sometimes logcat showed me network-entries twice,
            // which may will end in bugs)
        }
    }
} catch (NullPointerException | IllegalStateException e) {
    Log.e(TAG, "connectToWifi: Missing network configuration.");
}
return null;

前面的答案是可行的，但解决方案实际上可以更简单。循环通过配置的网络列表是不需要的，因为当你通过WifiManager添加网络时，你会得到网络id。

所以完整、简化的解决方案应该是这样的:

WifiConfiguration wifiConfig = new WifiConfiguration();
wifiConfig.SSID = String.format("\"%s\"", ssid);
wifiConfig.preSharedKey = String.format("\"%s\"", key);

WifiManager wifiManager = (WifiManager)getSystemService(WIFI_SERVICE);
//remember id
int netId = wifiManager.addNetwork(wifiConfig);
wifiManager.disconnect();
wifiManager.enableNetwork(netId, true);
wifiManager.reconnect();

你需要像这样创建wiificconfiguration实例:

String networkSSID = "test";
String networkPass = "pass";

WifiConfiguration conf = new WifiConfiguration();
conf.SSID = "\"" + networkSSID + "\"";   // Please note the quotes. String should contain ssid in quotes

然后，对于WEP网络，你需要这样做:

conf.wepKeys[0] = "\"" + networkPass + "\""; 
conf.wepTxKeyIndex = 0;
conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40); 

对于WPA网络，您需要添加这样的密码短语:

conf.preSharedKey = "\""+ networkPass +"\"";

对于开放网络，你需要这样做:

conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

然后，你需要将其添加到Android wifi管理器设置:

WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE); 
wifiManager.addNetwork(conf);

最后，你可能需要启用它，所以Android连接到它:

List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for( WifiConfiguration i : list ) {
    if(i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
         wifiManager.disconnect();
         wifiManager.enableNetwork(i.networkId, true);
         wifiManager.reconnect();               

         break;
    }           
 }

UPD:在WEP的情况下，如果您的密码是十六进制，您不需要用引号包围它。

获取Wifi列表，连接Wifi (Android <=9 and Android >=10)

[assembly: Xamarin.Forms.Dependency(typeof(WifiService))]
namespace configurator.Droid.Services
{
   public class WifiService : IWifiService
 {
    private bool _requested;
    private bool _statusConnect;

    private NetworkCallback _callback;
    private Context _context = null;
    private Version _version;
    private WifiManager _wifiManager = null;
    private ConnectivityManager _connectivityManager;
    private WifiConfiguration _config;
    private int _temp = -1;

    public WifiService()
    {
        this._context = Android.App.Application.Context;
        _version = DeviceInfo.Version;
        _wifiManager = _context.GetSystemService(Context.WifiService) as WifiManager;
    }

    [Obsolete]
    public async Task<bool> ConnectToWifiAsync(string ssid, string password, Action<bool> animation = null)
    {
        if (!_wifiManager.IsWifiEnabled)
        {
            if (_version.Major >= 9)
            {
                bool result =  await Device.InvokeOnMainThreadAsync(async () => await Application.Current.MainPage.DisplayAlert("", "The program requires accesss to Wi-Fi. Turn on Wi-fi?", "Ok", "Cancel")) ;

                if (!result)
                {
                    return false;
                }

                Intent intent;

                if (_version.Major == 9)
                {
                    intent = new Intent(Android.Provider.Settings.ActionWifiSettings);
                }
                else
                {
                    intent = new Intent(Android.Provider.Settings.Panel.ActionInternetConnectivity);
                }

                intent.AddFlags(ActivityFlags.NewTask);
                Android.App.Application.Context.StartActivity(intent);
            }
            else
            {
                _wifiManager.SetWifiEnabled(true);
            }
        }
        else
        {

            if (_version.Major <= 9 && _version.Major >= 8)
            {
                await Device.InvokeOnMainThreadAsync(async () => await Geolocation.GetLastKnownLocationAsync());
                JoinToWifiLessAndroidQAsync(ssid, password, animation);
            }
            else if(_version.Major < 8)
            {
                JoinToWifiLessAndroidQAsync(ssid, password, animation);
            }
            else
            {
                await Device.InvokeOnMainThreadAsync(async () => await Geolocation.GetLastKnownLocationAsync());
                await JoinToWifiMoreAndroidPie(ssid, password);
            }
        }
        
        return await Task.FromResult(_statusConnect);
    }

    [Obsolete]
    public async Task<IEnumerable<string>> GetAvailableNetworksAsync()
    {
        
        IEnumerable<string> availableNetworks = null;

        // Get a handle to the Wifi
        if (!_wifiManager.IsWifiEnabled)
            _wifiManager.SetWifiEnabled(true);
        var wifiReceiver = new WifiReceiver(_wifiManager);

        await Task.Run(() =>
        {
            // Start a scan and register the Broadcast receiver to get the list of Wifi Networks
            _context.RegisterReceiver(wifiReceiver, new IntentFilter(WifiManager.ScanResultsAvailableAction));
            availableNetworks = wifiReceiver.Scan();
        });

        return availableNetworks;
    }

    private class NetworkCallback : ConnectivityManager.NetworkCallback
    {
        private ConnectivityManager _connectivityManager;

        public NetworkCallback(ConnectivityManager connectivityManager)
        {
            _connectivityManager = connectivityManager;
        }
        public Action<Network> NetworkAvailable { get; set; }
        public Action NetworkUnavailable { get; set; }

        public override void OnAvailable(Network network)
        {
            _connectivityManager.BindProcessToNetwork(network);
            base.OnAvailable(network);
            NetworkAvailable?.Invoke(network);
        }

        public override void OnUnavailable()
        {
            base.OnUnavailable();
            NetworkUnavailable?.Invoke();
        }
    }

    [BroadcastReceiver(Enabled = true, Exported = false)]
    class WifiReceiver : BroadcastReceiver
    {
        private WifiManager _wifi;
        private List<string> _wifiNetworks;
        private AutoResetEvent _receiverARE;
        private Timer _tmr;
        private const int TIMEOUT_MILLIS = 20000; // 20 seconds timeout

        public WifiReceiver()
        {

        }

        public WifiReceiver(WifiManager wifi)
        {
            this._wifi = wifi;
            _wifiNetworks = new List<string>();
            _receiverARE = new AutoResetEvent(false);
        }

        [Obsolete]
        public IEnumerable<string> Scan()
        {
            _tmr = new Timer(Timeout, null, TIMEOUT_MILLIS, System.Threading.Timeout.Infinite);
            _wifi.StartScan();
            _receiverARE.WaitOne();
            return _wifiNetworks;
        }

        public override void OnReceive(Context context, Intent intent)
        {
            IList<ScanResult> scanwifinetworks = _wifi.ScanResults;
            foreach (ScanResult wifinetwork in scanwifinetworks)
            {
                _wifiNetworks.Add(wifinetwork.Ssid);
            }

            _receiverARE.Set();
        }

        private void Timeout(object sender)
        {
            // NOTE release scan, which we are using now, or we throw an error?
            _receiverARE.Set();
        }
    }

    [Obsolete]
    private void JoinToWifiLessAndroidQAsync(string ssid, string password, Action<bool> animation)
    {
        animation?.Invoke(true);

        _config = new WifiConfiguration
        {
            Ssid = "\"" + ssid + "\"",
            PreSharedKey = "\"" + password + "\""
        };

        try
        {
            _temp = _wifiManager.AddNetwork(_config);
            _wifiManager.Disconnect();
            var result = _wifiManager.EnableNetwork(_temp, true);
            _wifiManager.Reconnect();

            int i = 0;

            do
            {
                Thread.Sleep(2000);
                //wait connection
                i++;
                if (i == 7)
                    break;

            } while (GetCurrentConnectName() != ssid);

            Thread.Sleep(6000);

            if (i == 7)
            {
                throw new Exception("Connect to PC failed. Long time connect(14000ms)");
            }
            else
            {
                _statusConnect = true;
            }                
        }
        catch (Exception ex)
        {
            Helpers.Logger.Error($"{nameof(WifiService)}||JoinToWifiLessAndroidQ||{ex.Message}");
            _statusConnect = false;
        }
    }

    [Obsolete]
    private async Task<bool> JoinToWifiMoreAndroidPie(string ssid, string password)
    {
        var specifier = new WifiNetworkSpecifier.Builder()
                       .SetSsid(ssid)
                       .SetWpa2Passphrase(password)
                       .Build();
                      
        var request = new NetworkRequest.Builder()
                       .AddTransportType(TransportType.Wifi) 
                       .RemoveCapability(NetCapability.Internet) 
                       .SetNetworkSpecifier(specifier) 
                       .Build();

        _connectivityManager = _context.GetSystemService(Context.ConnectivityService) as ConnectivityManager;

        if (_requested)
        {
            _connectivityManager.UnregisterNetworkCallback(_callback);
        }

        bool confirmConnect = false;

        _callback = new NetworkCallback(_connectivityManager)
        {
            NetworkAvailable = network =>
            {
                // we are connected!
                _statusConnect = true;
                confirmConnect = true;
            },
            NetworkUnavailable = () =>
            {
                _statusConnect = false;
                confirmConnect = true;
            }
        };

        _connectivityManager.RequestNetwork(request, _callback);
        _requested = true;

        do
        {
            //wait callback
            await Task.Delay(TimeSpan.FromSeconds(5));
            Helpers.Logger.Info($"{nameof(WifiService)}||JoinToWifiMoreAndroidPie||Waiting callback....");

        } while (!confirmConnect);

        return await Task.FromResult(true);
    }

    public string GetCurrentConnectName()
    {
        WifiInfo wifiInfo = _wifiManager.ConnectionInfo;
        if (wifiInfo.SupplicantState == SupplicantState.Completed)
        {
            char[] chars = {'\"'};
            var masChar = wifiInfo.SSID.Trim(chars);
            return masChar;
        }
        else
        {
            return null;
        }
    }

    [Obsolete]
    public async Task ReconnectToWifi()
    {
        if (_version.Major > 9)
        {
            _connectivityManager.UnregisterNetworkCallback(_callback);
            await Task.Delay(10000);
            var network = _connectivityManager.ActiveNetwork;

            if(network == null)
            {
                var dataNetwork = await ManagerSecureStorage.GetConnectedNetworkInfo();
                await JoinToWifiMoreAndroidPie(dataNetwork["NetName"], dataNetwork["Password"]);
            }
            else
            {
                _connectivityManager.BindProcessToNetwork(network);
            }
        }
        else
        {
            if(_temp == -1)
            {
                var temp = _wifiManager.ConfiguredNetworks;
                _temp = temp.Last().NetworkId;
            }
            
            _wifiManager.RemoveNetwork(_temp);
            _wifiManager.Reconnect();
            await Task.Delay(10000);
        }
    }
  }
}

在API级别29中，WifiManager.enableNetwork()方法已弃用。根据Android API文档(点击这里查看):

请参阅WifiNetworkSpecifier.Builder#build()了解触发连接到Wi-Fi网络的新机制。 参见addnetworkrecommendations (java.util.List)， removenetworkrecommendations (java.util.List)获取添加Wi-Fi的新API 当自动连接到wifi时，考虑网络。兼容性 注意:对于以Build.VERSION_CODES为目标的应用程序。Q或以上，这个 API总是返回false。

从API级别29开始，要连接到WiFi网络，您将需要使用WifiNetworkSpecifier。您可以在https://developer.android.com/reference/android/net/wifi/WifiNetworkSpecifier.Builder.html#build(上找到示例代码)