开始一个新的活动

问题描述：

我有一个tabactivity，并在每个标签点击一个新的活动被调用。在每项活动中，我都可以选择使用NFC卡并获得价值。但问题是，当我在手机上点击卡片时，将调用一个新的活动，但没有作为父级的活动。代码在非Tabactivity中运行得非常好。开始一个新的活动

这是我的代码。

  adapter = NfcAdapter.getDefaultAdapter(this); 
      pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); 
      IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED); 
      tagDetected.addCategory(Intent.CATEGORY_DEFAULT); 
      writeTagFilters = new IntentFilter[] { tagDetected }; 
      ctx=this 


Now from drop down option I select tag 


    if(position == 2){ 
             mMsisdn_layout.setVisibility(View.GONE); 
             mNFC_layout.setVisibility(View.VISIBLE); 

             if(!adapter.isEnabled()){ 
              Toast.makeText(getApplicationContext(), "Please activate NFC and press Back to return to the application!", Toast.LENGTH_LONG).show(); 
              startActivity(new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS)); 
             } 

             else{ 
              mCustomizeDialog = new CustomizeDialog(this); 

              mCustomizeDialog.setTitle("NFC"); 
              mCustomizeDialog.setMessage("Please tap your NFC card"); 
              mCustomizeDialog.progressBar.setVisibility(View.INVISIBLE); 
              mCustomizeDialog.cancelButton.setVisibility(View.GONE); 
              mCustomizeDialog.okButton.setOnClickListener(new OnClickListener() { 


                 @Override 
                 public void onClick(View v) { 
                  if(mytag==null){ 
                   mCustomizeDialog.dismiss(); 

                  }else{ 
    //              mEdtNFC.setText(NfcidValue); 
                  mCustomizeDialog.dismiss(); 
                  } 
                 } 
              }); 
              mCustomizeDialog.show(); 
             } 



          } 



    /** 
    * 
    * @param text 
    * @param tag 
    * @throws IOException 
    * @throws FormatException 
    */ 
    private void write(String text, Tag tag) throws IOException, FormatException { 

     NdefRecord[] records = { createRecord(text) }; 
     NdefMessage message = new NdefMessage(records); 
     // Get an instance of Ndef for the tag. 
     Ndef ndef = Ndef.get(tag); 
     // Enable I/O 
     ndef.connect(); 
     // Write the message 
     ndef.writeNdefMessage(message); 
     // Close the connection 
     ndef.close(); 
    } 



    /** 
    * 
    * @param text 
    * @return 
    * @throws UnsupportedEncodingException 
    */ 
    private NdefRecord createRecord(String text) throws UnsupportedEncodingException { 
     String lang  = "en"; 
     byte[] textBytes = text.getBytes(); 
     byte[] langBytes = lang.getBytes("US-ASCII"); 
     int langLength = langBytes.length; 
     int textLength = textBytes.length; 
     byte[] payload = new byte[1 + langLength + textLength]; 

     // set status byte (see NDEF spec for actual bits) 
     payload[0] = (byte) langLength; 

     // copy langbytes and textbytes into payload 
     System.arraycopy(langBytes, 0, payload, 1,    langLength); 
     System.arraycopy(textBytes, 0, payload, 1 + langLength, textLength); 

     NdefRecord recordNFC = new NdefRecord(NdefRecord.TNF_UNKNOWN, NdefRecord.RTD_TEXT, new byte[0], payload); 

     return recordNFC; 
    } 


    /** 
    * 
    */ 
    @Override 
    protected void onNewIntent(Intent intent){ 
     if(NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())){ 
      mytag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); 

      Log.d("NFC intent", intent.getAction()); 
     // mytag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); 
//   System.out.println(myta); 
       Log.d("NFC tag", mytag.toString()); 
      // Log.d("NFC tag",bytesToHex(mytag.getId()).trim()); 
       NfcidValue = ConvertByteToHex.bytesToHex(mytag.getId()).trim(); 

       mEdtNFC.setText(NfcidValue); 
      // NfcidValue =""; 
       Toast.makeText(this,"Tap was successful", Toast.LENGTH_LONG).show(); 
     } 
    } 



    @Override 
    public void onPause(){ 
     super.onPause(); 
     WriteModeOff(); 
    } 

    /*@Override 
    public void onResume(){ 
     super.onResume(); 

    }*/ 

    /** 
    * 
    */ 
    private void WriteModeOn(){ 
     if(android.os.Build.VERSION.SDK_INT >= 16){ 
     writeMode = true; 
     adapter.enableForegroundDispatch(this, pendingIntent, writeTagFilters, null); 
     } 
    } 

    /** 
    * 
    */ 
    private void WriteModeOff(){ 
     if(android.os.Build.VERSION.SDK_INT >= 16){ 
     writeMode = false; 
     adapter.disableForegroundDispatch(this); 
     } 
    }

此代码工作正常，但我不明白为什么在标签活动中使用它时调用新的活动。

答

尝试处理TabActivity中的NFC意图。更好的是（从Android UI设计的角度来看）是重新设计应用程序，并在单个Activity（带有ActionBar）内使用Fragments在ViewPager中。那么你永远不会遇到这个问题。

开始一个新的活动

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