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NFC的在線源代碼使用「活動」完成。我想問問是否可以使用Fragment進行開發？使用片段的Android NFC開發
這是我打錯誤時我運行代碼
了java.lang.RuntimeException：無法實例活動ComponentInfo {com.mobile.countmein/com.mobile.countmein.activities.NFCScanner}：JAVA .lang.ClassCastException：com.mobile.countmein.activities.NFCScanner不能轉換到android.app.Activity
public class TagViewer extends Fragment {
private static final SimpleDateFormat TIME_FORMAT = new SimpleDateFormat();
private LinearLayout mTagContent;
private NfcAdapter mAdapter;
private PendingIntent mPendingIntent;
private NdefMessage mNdefPushMessage;
private AlertDialog mDialog;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.tag_viewer, container, false);
}
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mTagContent = (LinearLayout)view.findViewById(R.id.list);
resolveIntent(getActivity().getIntent());
mDialog = new AlertDialog.Builder(getActivity()).setNeutralButton("Ok", null).create();
mAdapter = NfcAdapter.getDefaultAdapter(getActivity());
if (mAdapter == null) {
showMessage(R.string.error, R.string.no_nfc);
}
mPendingIntent = PendingIntent.getActivity(getActivity(), 0,
new Intent(getActivity(), getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
mNdefPushMessage = new NdefMessage(new NdefRecord[] { newTextRecord(
"Message from NFC Reader :-)", Locale.ENGLISH, true) });
}
private void showMessage(int title, int message) {
mDialog.setTitle(title);
mDialog.setMessage(getText(message));
mDialog.show();
}
private NdefRecord newTextRecord(String text, Locale locale, boolean encodeInUtf8) {
byte[] langBytes = locale.getLanguage().getBytes(Charset.forName("US-ASCII"));
Charset utfEncoding = encodeInUtf8 ? Charset.forName("UTF-8") : Charset.forName("UTF-16");
byte[] textBytes = text.getBytes(utfEncoding);
int utfBit = encodeInUtf8 ? 0 : (1 << 7);
char status = (char) (utfBit + langBytes.length);
byte[] data = new byte[1 + langBytes.length + textBytes.length];
data[0] = (byte) status;
System.arraycopy(langBytes, 0, data, 1, langBytes.length);
System.arraycopy(textBytes, 0, data, 1 + langBytes.length, textBytes.length);
return new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT, new byte[0], data);
}
@Override
public void onResume() {
super.onResume();
if (mAdapter != null) {
if (!mAdapter.isEnabled()) {
showMessage(R.string.error, R.string.nfc_disabled);
}
mAdapter.enableForegroundDispatch(getActivity(), mPendingIntent, null, null);
mAdapter.enableForegroundNdefPush(getActivity(), mNdefPushMessage);
}
}
@Override
public void onPause() {
super.onPause();
if (mAdapter != null) {
mAdapter.disableForegroundDispatch(getActivity());
mAdapter.disableForegroundNdefPush(getActivity());
}
}
private void resolveIntent(Intent intent) {
String action = intent.getAction();
if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)
|| NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)
|| NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
NdefMessage[] msgs;
if (rawMsgs != null) {
msgs = new NdefMessage[rawMsgs.length];
for (int i = 0; i < rawMsgs.length; i++) {
msgs[i] = (NdefMessage) rawMsgs[i];
}
} else {
// Unknown tag type
byte[] empty = new byte[0];
byte[] id = intent.getByteArrayExtra(NfcAdapter.EXTRA_ID);
Parcelable tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
byte[] payload = dumpTagData(tag).getBytes();
NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, id, payload);
NdefMessage msg = new NdefMessage(new NdefRecord[] { record });
msgs = new NdefMessage[] { msg };
}
// Setup the views
buildTagViews(msgs);
}
}
private String dumpTagData(Parcelable p) {
StringBuilder sb = new StringBuilder();
Tag tag = (Tag) p;
byte[] id = tag.getId();
sb.append("Tag ID (hex): ").append(getHex(id)).append("\n");
sb.append("Tag ID (dec): ").append(getDec(id)).append("\n");
String prefix = "android.nfc.tech.";
sb.append("Technologies: ");
for (String tech : tag.getTechList()) {
sb.append(tech.substring(prefix.length()));
sb.append(", ");
}
sb.delete(sb.length() - 2, sb.length());
for (String tech : tag.getTechList()) {
if (tech.equals(MifareClassic.class.getName())) {
sb.append('\n');
MifareClassic mifareTag = MifareClassic.get(tag);
String type = "Unknown";
switch (mifareTag.getType()) {
case MifareClassic.TYPE_CLASSIC:
type = "Classic";
break;
case MifareClassic.TYPE_PLUS:
type = "Plus";
break;
case MifareClassic.TYPE_PRO:
type = "Pro";
break;
}
sb.append("Mifare Classic type: ");
sb.append(type);
sb.append('\n');
sb.append("Mifare size: ");
sb.append(mifareTag.getSize() + " bytes");
sb.append('\n');
sb.append("Mifare sectors: ");
sb.append(mifareTag.getSectorCount());
sb.append('\n');
sb.append("Mifare blocks: ");
sb.append(mifareTag.getBlockCount());
}
if (tech.equals(MifareUltralight.class.getName())) {
sb.append('\n');
MifareUltralight mifareUlTag = MifareUltralight.get(tag);
String type = "Unknown";
switch (mifareUlTag.getType()) {
case MifareUltralight.TYPE_ULTRALIGHT:
type = "Ultralight";
break;
case MifareUltralight.TYPE_ULTRALIGHT_C:
type = "Ultralight C";
break;
}
sb.append("Mifare Ultralight type: ");
sb.append(type);
}
}
return sb.toString();
}
private String getHex(byte[] bytes) {
StringBuilder sb = new StringBuilder();
for (int i = bytes.length - 1; i >= 0; --i) {
int b = bytes[i] & 0xff;
if (b < 0x10)
sb.append('0');
sb.append(Integer.toHexString(b));
if (i > 0) {
sb.append(" ");
}
}
return sb.toString();
}
private long getDec(byte[] bytes) {
long result = 0;
long factor = 1;
for (int i = 0; i < bytes.length; ++i) {
long value = bytes[i] & 0xffl;
result += value * factor;
factor *= 256l;
}
return result;
}
void buildTagViews(NdefMessage[] msgs) {
if (msgs == null || msgs.length == 0) {
return;
}
LayoutInflater inflater = LayoutInflater.from(getActivity());
LinearLayout content = mTagContent;
// Parse the first message in the list
// Build views for all of the sub records
Date now = new Date();
List<ParsedNdefRecord> records = NdefMessageParser.parse(msgs[0]);
final int size = records.size();
for (int i = 0; i < size; i++) {
TextView timeView = new TextView(getActivity());
timeView.setText(TIME_FORMAT.format(now));
content.addView(timeView, 0);
ParsedNdefRecord record = records.get(i);
content.addView(record.getView(getActivity(), inflater, content, i), 1 + i);
content.addView(inflater.inflate(R.layout.tag_divider, content, false), 2 + i);
}
}
}
予移除下列因爲片段不具有第e方法：
@Override
public void onNewIntent(Intent intent) {
setIntent(intent);
resolveIntent(intent);
}