识别NFC标签ID [英] Identifying NFC tag ID

问题描述

我正在尝试使用以下代码在android上识别NFC标签的唯一标识符:

I am trying to identify the unique identifier of NFC tag on android using the following code:

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 Tag myTag = (Tag) getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG);
 String nFCID = myTag.getId().toString();   
 Toast.makeText(getApplicationContext(), "NFC id is: "+ nFCID, Toast.LENGTH_SHORT).show();      
}

不幸的是，当我将应用程序部署到真实设备并扫描NFC标签时，我的应用程序将崩溃，提示不幸的是xyz必须停止...". 我知道getID()将返回字节数组，我必须将其解析为String.但是至少我希望这段代码返回一些值，而不是使应用程序崩溃.有任何解决方法的想法吗?

Unfortunately, when I deploy the app to a real device and scan an NFC tag, my app will crash stating "Unfortunately xyz has to stop...". I know getID() will return byte array and I have to parse it to String. But at least I expect this code to return some values rather than crashing the app. Any ideas how to fix it?

已LogCat输出:

W/dalvikvm(25548): threadid=1: thread exiting with uncaught exception group=0x41b652a0)
E/AndroidRuntime(25548): FATAL EXCEPTION: main
E/AndroidRuntime(25548): java.lang.RuntimeException: 
Unable to start activity ComponentInfo{com.xyz.nfcid/com.xyz.nfcid.MainActivity}: 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100)

推荐答案

我很确定，您的标签为空.您应该先检查字符串操作

I'm pretty sure, that your tag is null. You should check the action String first

String action = intent.getAction();
if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
    //... do something
}

我已经写了完整的教程，它应该会对您有所帮助.

I've written a complete tutorial, which should help you.

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