c# - NFC Action_Tech_Discovered with foreground dispatch won't catch Mifare 1k card -

i'm coding in c# xamarin , trying scan mifare classic 1k card nfc.

the intent-filter of m1card_test working fine. don't want select activity want start. i'm trying use foreground dispatch.

here part of code (c#):

• oncreate

  intent myintent = new intent(this, gettype()); myintent.addflags(activityflags.singletop); mpendingintent = pendingintent.getactivity(this, 0, myintent, 0);  ndefdetected = new intentfilter(nfcadapter.actiontechdiscovered); ndefdetected.adddatatype("*/*");  intentf = new intentfilter[] { ndefdetected }; techlists = new string[][] {new string[] {     typeof(android.nfc.tech.nfca).fullname,     typeof(android.nfc.tech.mifareclassic).fullname} }; 

• onpause

  nfcmanager manager = (nfcmanager)getsystemservice(nfcservice); manager.defaultadapter.disableforegrounddispatch(this); 

• onresume

  nfcmanager manager = (nfcmanager)getsystemservice(nfcservice); manager.defaultadapter.enableforegrounddispatch(this,mpendingintent,intentf,techlists); 

unfortunately, foreground dispatch doesn't work (i.e. not pick tag).

if change call enableforegrounddispatch() to

manager.defaultadapter.enableforegrounddispatch(this,mpendingintent,null,null); 

the foreground dispatch work fine. picks tags , not mifare classic , intent action_tag_discovered instead of action_tech_discovered.

how use action_tech_discovered foreground dispatch system?

did miss something?

---

tech_list.xml:

<?xml version="1.0" encoding="utf-8" ?> <resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">   <tech-list>     <tech>android.nfc.tech.nfca</tech>     <tech>android.nfc.tech.mifareclassic</tech>   </tech-list>   </resources> 

androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="m1card_test.m1card_test" android:versioncode="1" android:versionname="1.0">   <uses-sdk android:minsdkversion="16" />   <application android:label="m1card_test"></application>   <uses-permission android:name="android.permission.nfc" /> </manifest> 

my c# code:

using system; using system.collections.generic; using system.linq; using system.text; using android.app; using android.content; using android.os; using android.runtime; using android.views; using android.widget; using android.nfc;  namespace m1card_test {     [activity(label = "m1_read",  icon = "@drawable/icon", launchmode = android.content.pm.launchmode.singletask)]     [intentfilter(     new[] {nfcadapter.actiontechdiscovered},      categories = new[] {intent.categorydefault,})]     [metadata("android.nfc.action.tech_discovered", resource = "@xml/tech_list")]      public class m1_read : activity     {         textview mtv;         pendingintent mpendingintent;         intentfilter ndefdetected;         intentfilter[] intentf;         string[][] techlists;          protected override void oncreate(bundle savedinstancestate)         {             base.oncreate(savedinstancestate);             setcontentview(resource.layout.m1_read);              intent myintent = new intent(this, gettype());             myintent.addflags(activityflags.singletop);             mpendingintent = pendingintent.getactivity(this, 0, myintent, 0);              ndefdetected = new intentfilter(nfcadapter.actiontechdiscovered);             ndefdetected.adddatatype("*/*");              intentf = new intentfilter[] { ndefdetected };             techlists = new string[][] {new string[] {                 typeof(android.nfc.tech.nfca).fullname,                 typeof(android.nfc.tech.mifareclassic).fullname}             };              button button = findviewbyid<button>(resource.id.back_button);             mtv = findviewbyid<textview>(resource.id.textview);             button.click += delegate             {                 intent main_intent = new intent(this, typeof(mainactivity));                 this.startactivity(main_intent);                 finish();             };          }         protected override void onpause()         {             base.onpause();             nfcmanager manager = (nfcmanager)getsystemservice(nfcservice);             manager.defaultadapter.disableforegrounddispatch(this);         }          protected override void onresume()         {             base.onresume();             nfcmanager manager = (nfcmanager)getsystemservice(nfcservice);             manager.defaultadapter.enableforegrounddispatch(this, mpendingintent,intentf,techlists);         }          protected override void onnewintent(intent intent)         {             base.onnewintent(intent);             mtv.text = "onnewintent";         }     } } 

the tech_discovered intent filter not have data-type (mime type) associated it. need remove line

ndefdetected.adddatatype("*/*"); 

moreover, i'm not quite sure if typeof(android.nfc.tech.mifareclassic).fullname resolves correct name (full java class name) of tag technology. thus, should hard-code string (just in tech-filter xml file):

techlists = new string[][] { new string[] {     "android.nfc.tech.nfca",     "android.nfc.tech.mifareclassic" }}; 

finally, since mifareclassic tag technology implies nfca, can safely reduce tech-filter just

techlists = new string[][] { new string[] {     "android.nfc.tech.mifareclassic" }};