一、前提条件，App必须具有NFC权限。

 

二、项目中加入监控类NFCCatchActivity.cs

[Activity(Label = "NFCCatch",Theme = "@android:style/Theme.NoDisplay")]    [IntentFilter(new[] { "android.nfc.action.TECH_DISCOVERED" })]    [MetaData("android.nfc.action.TECH_DISCOVERED", Resource = "@xml/nfc_tech_filter")]    public class NFCCatchActivity : Activity    {        NfcAdapter mNfcAdapter;        PendingIntent mPendingIntent;        protected override void OnCreate(Bundle savedInstanceState)        {            base.OnCreate(savedInstanceState);            mNfcAdapter = NfcAdapter.GetDefaultAdapter(this);            if (mNfcAdapter == null)            {                //textViewNFC.Text = "NFC is not available on this device.";            }            else            {                mPendingIntent = PendingIntent.GetActivity(this, 0, new Intent(this,                typeof(NFCCatchActivity)), PendingIntentFlags.UpdateCurrent);                OnNewIntent(Intent);            }        }        protected override void OnResume()        {            base.OnResume();            if (mNfcAdapter != null)                mNfcAdapter.EnableForegroundDispatch(this, mPendingIntent, null, null);        }        protected override void OnPause()        {            base.OnPause();            if (mNfcAdapter != null)                mNfcAdapter.DisableForegroundDispatch(this);        }        public static string ByteArrayToString(byte[] ba)        {            string hex = BitConverter.ToString(ba);            string rtnStr = "";            string timeN = DateTime.Now.ToString("ssmmHHddMMyyMMyyddHHmmssMMddHHmm");            string tmp1 = "";            string tmp2 = "";            }            rtnStr = tmp1 + hex + tmp2;            return rtnStr;        }        protected override void OnNewIntent(Intent intent)        {            base.OnNewIntent(intent);            Intent = intent;            Tag tag = (Tag)intent.GetParcelableExtra(NfcAdapter.ExtraTag);            string cardID = ByteArrayToString(tag.GetId());//本活动为后台运行，在获取到IC卡号之后，调用主活动中的方法处理实际业务，如反馈给H5页面。            MainActivity.instance.SetNFCData(cardID);        }    }

 

三、与之相关的主活动方法

public void SetNFCData(string nfcid)        {            //EvaluateJavascript不会刷新页面            //调用H5页面的函数，赋值给文本框或变量都可以            string script = "javascript:SetNFCID('"+ nfcid + "');";            web_view.EvaluateJavascript(script, null);        }

四、由此，就可以实现在终端上感应源，获取源的信息到Web页面之中了。