Android的读/写于多个记录NDEF NFC [英] Android Read/Write to Multiple Records NDEF NFC

问题描述

我想写和在NDEFMessage多个记录读取/。是我的$ C $其中，C吧？另外，我的进程终止本身，当我读标签。我不知道我在哪里出了错。

写作部分：

 私人NdefMessage getTagAsNdef（）{
           字符串text123 =你好;
            //布尔addAAR = TRUE;
            字符串UNIQUEID =starbucks.com;
         字节[] = uriField uniqueId.getBytes（Charset.forName（US-ASCII））;
         字节[] =有效载荷新的字节[uriField.length + 1]; //加1为URI preFIX
         有效载荷[0] = 0×01; // prefixes HTTP：// WWW。的URI
         System.arraycopy（uriField，0，有效载荷，1，uriField.length）; // URI追加有效载荷
         NdefRecord rtdUriRecord =新NdefRecord（
           NdefRecord.TNF_WELL_KNOWN，NdefRecord.RTD_URI，新的字节[0]，负载）;
         //无线网络连接测试写入code
         字节[] = textbytes text123.getBytes（）;
         NdefRecord textRecord =新NdefRecord（NdefRecord.TNF_WELL_KNOWN，
                 text123.getBytes（），新的字节[] {}，textbytes）;
         如果（android.os.Build.VERSION.SDK_INT＆GT; = android.os.Build.VERSION_ codeS.ICE_CREAM_SANDWICH）{
              //注：返回AAR为不同的应用程序（couponmanager）
              返回新NdefMessage（新NdefRecord [] {
           rtdUriRecord，textRecord，NdefRecord.createApplicationRecord（com.example.ponpon）
         }）;
         }其他{
              返回新NdefMessage（新NdefRecord [] {
                   rtdUriRecord，textRecord}）;
         }
       }
 

阅读部分：

  @覆盖
        保护无效onNewIntent（意向意图）{
            super.onNewIntent（意向）;
            共享preferences preferences = getShared preferences（preF_FILE_NAME，MODE_PRIVATE）;
            诠释存储preference = preferences.getInt（storedInt，0）;            如果（NfcAdapter.ACTION_NDEF_DISCOVERED.equals（intent.getAction（）））{
                NdefMessage []消息= NULL;
                Parcelable [] = rawMsgs intent.getParcelableArrayExtra（NfcAdapter.EXTRA_NDEF_MESSAGES）;
                如果（rawMsgs！= NULL）{
                    消息=新NdefMessage [rawMsgs.length]
                    的for（int i = 0; I＆LT; rawMsgs.length;我++）{
                        消息[I] =（NdefMessage）rawMsgs [I]
                    }
                }
                如果（讯息[0]！= NULL）{
                    字符串结果=;
                    字节[] =有效载荷的消息[0] .getRecords（）[0] .getPayload（）;                    //这个假设，我们找回我SOH其次是主机/ code
                    对于（INT B = 1; B＆LT; payload.length; b ++）{//跳过SOH
                        结果+ =（char）的有效载荷[B]。
                    }
                    //抓住第二个有效载荷
                    字符串RESULT2 =;
                    字节[] payload2 =消息[0] .getRecords（）[1] .getPayload（）;
                    对于（INT测试= 1;测试＆LT; payload2.length;试验++）{//跳过SOH
                        结果2 + =（char）的payload2 [测试]
                        Toast.makeText（这一点，结果2，Toast.LENGTH_SHORT）.show（）;                    }
 

解决方案

你跳过第一个字节即H.
在第一个记录你pre-未决读取数据时，你正确地跳过一个字节。

至于速度我那只是操作系统缓冲祝酒词

I'm trying to write and read to/from multiple records in a NDEFMessage. Is my code here right? Also, my process terminates itself when I'm reading the tag. I'm not sure where I went wrong..

Writing part:

private NdefMessage getTagAsNdef() {  
           String text123="Hello";
            //boolean addAAR = true;  
            String uniqueId = "starbucks.com";      
         byte[] uriField = uniqueId.getBytes(Charset.forName("US-ASCII"));  
         byte[] payload = new byte[uriField.length + 1];       //add 1 for the URI Prefix  
         payload[0] = 0x01;                        //prefixes http://www. to the URI  
         System.arraycopy(uriField, 0, payload, 1, uriField.length); //appends URI to payload  
         NdefRecord rtdUriRecord = new NdefRecord(  
           NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_URI, new byte[0], payload);  
         //Wi-FI test writing code
         byte[] textbytes = text123.getBytes();
         NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_WELL_KNOWN, 
                 text123.getBytes(), new byte[]{}, textbytes);


         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {  
              // note: returns AAR for different app (couponmanager)  
              return new NdefMessage(new NdefRecord[] {  
           rtdUriRecord, textRecord, NdefRecord.createApplicationRecord("com.example.ponpon")  
         });   
         } else {  
              return new NdefMessage(new NdefRecord[] {  
                   rtdUriRecord,textRecord});  
         }  
       }  

Reading part:

@Override
        protected void onNewIntent(Intent intent) {
            super.onNewIntent(intent);      
            SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
            int storedPreference = preferences.getInt("storedInt", 0);

            if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
                NdefMessage[] messages = null;
                Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
                if (rawMsgs != null) {
                    messages = new NdefMessage[rawMsgs.length];
                    for (int i = 0; i < rawMsgs.length; i++) {
                        messages[i] = (NdefMessage) rawMsgs[i];
                    }
                }
                if(messages[0] != null) {
                    String result="";
                    byte[] payload = messages[0].getRecords()[0].getPayload();



                    // this assumes that we get back am SOH followed by host/code
                    for (int b = 1; b<payload.length; b++) { // skip SOH
                        result += (char) payload[b];
                    }


                    //grabbing 2nd payload
                    String result2="";
                    byte[] payload2 = messages[0].getRecords()[1].getPayload();
                    for (int test = 1; test<payload2.length; test++) { // skip SOH
                        result2 += (char) payload2[test];
                        Toast.makeText(this,result2,Toast.LENGTH_SHORT).show();  

                    }

解决方案

You're skipping the first byte i.e. the H. In the first record you're pre-pending a byte which you correctly skip when reading.

As for speed I thats just the OS buffering the toasts

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