Question

我想将nfcID从resolveIntent（）函数传递到下一个intent或接口。我已尝试将下面的代码放入函数

Intent i = new Intent(NFCLogin.this, User.class);
i.putExtra("nfcID",nfcID);
startActivity(i);

然后应用程序崩溃了。请帮我。

package com.example.johnJones.passkiller;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.PendingIntent;
import android.content.IntentFilter;
import android.nfc.NfcAdapter;
import android.nfc.tech.IsoDep;  
import android.nfc.tech.MifareClassic;
import android.nfc.tech.MifareUltralight;
import android.nfc.tech.Ndef; 
import android.nfc.tech.NfcA;
import android.nfc.tech.NfcB; 
import android.nfc.tech.NfcF;
import android.nfc.tech.NfcV;
import android.widget.Toast;
import android.widget.TextView;

public class NFCLogin extends AppCompatActivity {

private final String[][] techList = new String[][] {
        new String[] {
                NfcA.class.getName(),
                NfcB.class.getName(),
                NfcF.class.getName(),
                NfcV.class.getName(),
                IsoDep.class.getName(),
                MifareClassic.class.getName(),
                MifareUltralight.class.getName(), Ndef.class.getName()
        }
};

String nfcID = "";
NfcAdapter mAdapter;
//DatabaseHelper helper = new DatabaseHelper(this);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_nfclogin);

}

@Override
protected void onResume() {
    super.onResume();
    // creating pending intent:
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
    // creating intent receiver for NFC events:
    IntentFilter filter = new IntentFilter();
    filter.addAction(NfcAdapter.ACTION_TAG_DISCOVERED);
    filter.addAction(NfcAdapter.ACTION_NDEF_DISCOVERED);
    filter.addAction(NfcAdapter.ACTION_TECH_DISCOVERED);
    // enabling foreground dispatch for getting intent from NFC event:
    NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
    nfcAdapter.enableForegroundDispatch(this, pendingIntent, new IntentFilter[]{filter}, this.techList);
}

@Override
protected void onPause() {
    super.onPause();
    // disabling foreground dispatch:
    NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
    nfcAdapter.disableForegroundDispatch(this);
}

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    resolveIntent(intent);
}

private void resolveIntent(Intent intent){
    String action = intent.getAction();
    if (action.equals(NfcAdapter.ACTION_TAG_DISCOVERED)) {
        nfcID = ByteArrayToHexString(intent.getByteArrayExtra(NfcAdapter.EXTRA_ID));
        Toast.makeText(NFCLogin.this, nfcID, Toast.LENGTH_SHORT).show();

    }
}


private String ByteArrayToHexString(byte [] inarray) {
    int i, j, in;
    String [] hex = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};
    String out= "";

    for(j = 0 ; j < inarray.length ; ++j)
    {
        in = (int) inarray[j] & 0xff;
        i = (in >> 4) & 0x0f;
        out += hex[i];
        i = in & 0x0f;
        out += hex[i];
    }
    return out;
}
}

我想将nfcID传递给下一个接口，即User.class，但应用程序崩溃。

Answer 1

这就是我将NFC意图传递给另一个活动的方式（此处名为ResultActivity）：

Intent mainintent = getIntent(); if (mainintent.getAction().equals(NfcAdapter.ACTION_NDEF_DISCOVERED)) { //transfer the NDEF data to a new intent Parcelable[] rawMsgs = mainintent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); Intent myintent = new Intent(this, ResultActivity.class); myintent.setAction(NfcAdapter.ACTION_NDEF_DISCOVERED); myintent.putExtra(NfcAdapter.EXTRA_NDEF_MESSAGES, rawMsgs); myintent.putExtra(NfcAdapter.EXTRA_TAG, mainintent.getParcelableExtra(NfcAdapter.EXTRA_TAG)); startActivity(myintent); }

如何将NFC tagInfo从一个意图转移到另一个意图（一个接口到另一个接口）？

1 个答案: