Question

I have made an NFC tag writing app that has various options such as writing text,URL,toggle Wifi, Business Card etc.
The problem i am facing is when i click the write button after entering text. The app terminates on itself.
May be i am calling the wrong method.

当用户从列表中选择“写入URL”时，我希望这样。然后写入URL活动应该开始，并在按下写入按钮时写入标记。现在，当我按下写标签按钮。该应用程序说“不幸的是应用程序已停止。”

ListDisplay

    package com.example.jordjr.projectwork;

import android.content.Intent;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class ListDisplay extends Activity implements AdapterView.OnItemClickListener {
    // Array of strings...

    ListView listview;
    String[] mobileArray = {"Text", "URL", "Email", "Phone Number", "Wifi", "Business Card"};

    @Override

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);

        ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.activity_listview, mobileArray);

        listview = (ListView) findViewById(R.id.mobile_list);
        listview.setAdapter(adapter);

        listview.setOnItemClickListener(this);
            }


    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {



        String item = ((TextView) view).getText().toString();

        if(item.equalsIgnoreCase("text")){
            Intent intent=new Intent (this,WriteUrl.class);
            startActivity(intent);
        }
        else
        if(item.equalsIgnoreCase("Phone Number")){
            Intent intent=new Intent (this,PhoneNumber.class);
            startActivity(intent);

        }
        else
        if(item.equalsIgnoreCase("URL")) {
            Intent intent = new Intent(this, WriteUrl.class);
            startActivity(intent);
        }
            else
            if(item.equalsIgnoreCase("Wifi")) {
                Intent intent = new Intent(this,Wifi.class);
                startActivity(intent);
            }
            else
            if(item.equalsIgnoreCase("Email")) {
                Intent intent = new Intent(this,WriteEmail.class);
                startActivity(intent);
            }
            else
            if(item.equalsIgnoreCase("Business Card")) {
                Intent intent = new Intent(this, BusinessCard.class);
                startActivity(intent);
            }


    }

    }

写网址 package com.example.jordjr.projectwork;

import android.app.PendingIntent;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.Uri;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.nfc.tech.NdefFormatable;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class WriteUrl extends AppCompatActivity {



    NfcAdapter nfcAdapter;
    Button button;
    EditText txtTagContent;
    int x=0;

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

        nfcAdapter=NfcAdapter.getDefaultAdapter(this);
        button = (Button)findViewById(R.id.button);
        txtTagContent = (EditText)findViewById(R.id.txtTagContent);

    }


    @Override
    protected void onResume() {
        super.onResume();
        enableForegroundDispatchSystem();
    }

    @Override
    protected void onPause() {
        super.onPause();

        disableForegroundDispatchSystem();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }



    private void enableForegroundDispatchSystem()
    {
        Intent intent=new Intent(this, MainActivity.class).addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);

        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);

        IntentFilter[] intentFilters = new IntentFilter[] {};

        nfcAdapter.enableForegroundDispatch(this, pendingIntent, intentFilters, null);
    }


    private void disableForegroundDispatchSystem()
    {
        nfcAdapter.disableForegroundDispatch(this);

    }

    private void formatTag(Tag tag,NdefMessage ndefMessage)
    {
        try
        {
            NdefFormatable ndefFormatable=NdefFormatable.get(tag);

            if(ndefFormatable == null)
            {
                Toast.makeText(this, "This Tag is Not ndef Formatable!", Toast.LENGTH_SHORT).show();
            }
            ndefFormatable.connect();
            ndefFormatable.format(ndefMessage);
            ndefFormatable.close();
            Toast.makeText(this, "Tag written", Toast.LENGTH_SHORT).show();
        }
        catch (Exception e)
        {
            Log.e("formatTag", e.getMessage());

        }
    }


    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        if (x == 1) {
            if (intent.hasExtra(NfcAdapter.EXTRA_TAG)) {
                Toast.makeText(this, "NfcIntent!", Toast.LENGTH_SHORT).show();


                Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
                NdefMessage ndefMessage = createNdefMessage(txtTagContent.getText() + "");

                writeNdefMessage(tag, ndefMessage);

            }
            x=0;
        }
    }
    private void writeNdefMessage(Tag tag, NdefMessage ndefMessage)
    {
        try
        {
            if(tag == null)
            {
                Toast.makeText(this, "Tag object cannot be null", Toast.LENGTH_SHORT).show();
                return;
            }

            Ndef ndef = Ndef.get(tag);

            if(ndef == null)
            {
                //formats tag with the ndef format and writes the message
                formatTag(tag, ndefMessage);
            }

            else
            {
                ndef.connect();

                if(!ndef.isWritable())
                {
                    Toast.makeText(this, "Tag is not writable!", Toast.LENGTH_SHORT).show();
                    ndef.close();
                    return;
                }

                ndef.writeNdefMessage(ndefMessage);
                ndef.close();

                Toast.makeText(this, "Tag written", Toast.LENGTH_SHORT).show();
            }
        }
        catch(Exception e)
        {

            Log.e("writeNdefMessage", e.getMessage());
        }
    }

    private NdefMessage createNdefMessage(String content)
    {

        NdefRecord ndefRecord = createUrlRecord(content);

        NdefMessage ndefMessage=new NdefMessage(new NdefRecord[] {ndefRecord});

        return ndefMessage;
    }

    private NdefRecord createUrlRecord(String content)
    {
        try {
            Uri uri = Uri.parse("http://" + content);
            NdefRecord ndefRecord = NdefRecord.createUri(uri);
            return ndefRecord;
        }
        catch(Exception e)
        {
            Log.e("create Ndef Record", e.getMessage());
            return null;
        }
    }

    public void writeUri(View view) {
        Toast.makeText(this, "Bring forth thy nfc tag", Toast.LENGTH_SHORT).show();
        x=1;
    }
}

xml文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingRight="16dp"
android:paddingTop="16dp"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
tools:context="com.example.jordjr.projectwork.WriteUrl">



    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="WRITE URL"
        android:checked="true"
        android:onClick="writeUri"
        />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:id="@+id/txtTagContent"
        android:layout_gravity="top"
        android:height="40dp"
        android:width="320dp"
        android:text="Enter Here"
    enter code here

        />






</RelativeLayout>

Answer 1

我无法发表评论。您是否在清单中声明了所有活动？像：

   <activity
           android:name=".WriteUrl">
    </activity>
    <activity
            android:name=".PhoneNumber">
    </activity>

......等等？

按下按钮＆＃34;写＆＃34;一项新活动已经开始。如果未宣布该活动，那么应用程序肯定会粉碎并显示消息＆＃34;不幸的是该应用程序已停止。＆＃34;。

无法使用文本或URL写入NFC标记

1 个答案: