Android NFC Development Combat

The beam example provided in the Android 4.0 SDK is indeed a good template for NFC development. Consider the following code for NDEF message processing that understands NFC.

public class Beam extends activity implements Createndefmessagecallback,

Onndefpushcompletecallback {

Nfcadapter Mnfcadapter;

TextView Minfotext;

private static final int message_sent = 1;

@Override

public void OnCreate (Bundle savedinstancestate) {

Super.oncreate (savedinstancestate);

Setcontentview (R.layout.main);

Minfotext = (TextView) Findviewbyid (R.id.textview);

Mnfcadapter = Nfcadapter.getdefaultadapter (this); Instantiating NFC devices

if (Mnfcadapter = = null) {

Minfotext = (TextView) Findviewbyid (R.id.textview);

Minfotext.settext ("NFC isn't available on this device.");

}

　　

Mnfcadapter.setndefpushmessagecallback (this, this); Registering NDEF callback messages

Mnfcadapter.setonndefpushcompletecallback (this, this);

}

　　

@Override

Public ndefmessage Createndefmessage (Nfcevent event) {

Time is = new Time ();

Time.settonow ();

String Text = ("Beam Me Up!nn" +

"Beam Time:" + Time.format ("%h:%m:%s"));

Ndefmessage msg = new Ndefmessage (

New ndefrecord[] {Createmimerecord (

"Application/com.example.android.beam", Text.getbytes ())

});

return msg;

}

@Override

public void Onndefpushcomplete (Nfcevent arg0) {

A handler is needed to send messages to the

Callback occurs, because it happens from a binder thread

Mhandler.obtainmessage (message_sent). Sendtotarget ();

}

Private final Handler Mhandler = new Handler () {

@Override

public void Handlemessage (msg) {

Switch (msg.what) {

Case Message_sent:

Toast.maketext (Getapplicationcontext (), "Message sent!", Toast.length_long). Show ();

Break

}

}

};

@Override

public void Onresume () {

Super.onresume ();

if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals (Getintent (). Getaction ())) {

Processintent (Getintent ());

}

}

@Override

public void Onnewintent (Intent Intent) {

Onresume gets called to handle the intent

Setintent (Intent);

}

/**

* Parses the NDEF message from the intent and prints to the TextView

*/

void Processintent (Intent Intent) {

parcelable[] Rawmsgs = Intent.getparcelablearrayextra (

Nfcadapter.extra_ndef_messages);

Only one message sent during the beam

Ndefmessage msg = (ndefmessage) rawmsgs[0];

Record 0 contains the MIME type, record 1 is the AAR, if present

Minfotext.settext (New String (Msg.getrecords () [0].getpayload ()));

}

/**

* Creates a custom MIME type encapsulated in the Ndef record

*

* @param mimetype

*/

Public Ndefrecord Createmimerecord (String mimetype, byte[] payload) {

byte[] mimebytes = mimetype.getbytes (Charset.forname ("Us-ascii"));

Ndefrecord Mimerecord = new Ndefrecord (

Ndefrecord.tnf_mime_media, Mimebytes, new byte[0], payload);

return Mimerecord;

}

@Override

public boolean Oncreateoptionsmenu (Menu menu) {

If NFC is not available, we won ' t being needing this menu

if (Mnfcadapter = = null) {

return Super.oncreateoptionsmenu (menu);

}

Menuinflater inflater = Getmenuinflater ();

Inflater.inflate (r.menu.options, menu);

return true;

}

@Override

public boolean onoptionsitemselected (MenuItem item) {

Switch (Item.getitemid ()) {

Case R.id.menu_settings:

Intent Intent = new Intent (settings.action_nfcsharing_settings);

StartActivity (Intent);

return true;

Default

return super.onoptionsitemselected (item);

}

}

}