我的ProgressBar在执行过程中不会显示。
我的应用程序读取NFC消息。有必要在阅读过程中显示ProgressBar，并在TextView中显示有关它的消息。阅读完成后，ProgressBar消失，＆＃34;成功＆＃34;被展示。
但它对我不起作用。
public class NFCReadFragment extends DialogFragment {
public static final String TAG = NFCReadFragment.class.getSimpleName();
public static NFCReadFragment newInstance() {
return new NFCReadFragment();
}
private TextView mTvMessage;
private Listener mListener;
private ProgressBar mProgres;
OnReadDataPass onReadDataPass;
public interface OnReadDataPass {
void onReadDataPass(byte[][] data);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_read,container,false);
initViews(view);
return view;
}
private void initViews(View view) {
mTvMessage = (TextView) view.findViewById(R.id.tv_message);
mProgres = (ProgressBar) view.findViewById(R.id.progressBarRead);
mProgres.setVisibility(View.GONE);
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
mListener = (MainActivity) context;
mListener.onDialogDisplayed();
onReadDataPass = (OnReadDataPass) context;
}
@Override
public void onDetach() {
super.onDetach();
mListener.onDialogDismissed();
}
public void passReadData(byte[][] data){
onReadDataPass.onReadDataPass(data);
}
public void onNfcDetected(Ndef ndef){
mProgres.setVisibility(View.VISIBLE);
byte[][] buf = readFromNFC(ndef);
if(buf != null) {
passReadData(buf);
}
}
private byte[][] readFromNFC(Ndef ndef) {
mTvMessage.setText("Идёт процесс считывания");
try {
ndef.connect();
NdefMessage ndefMessage = ndef.getNdefMessage();
if(ndefMessage != null) {
byte buf[][] = new byte[ndefMessage.getRecords().length][];
for (int i = 0; i < ndefMessage.getRecords().length; i++) {
buf[i] = ndefMessage.getRecords()[i].getPayload();
}
Log.d(TAG, "readFromNFC: " + "success");
mTvMessage.setText("Успешно");
ndef.close();
return buf;
}
else{
Log.d(TAG, "readFromNFC: " + "NFC tag null");
mTvMessage.setText("Ошибка чтения");
return null;
}
} catch (IOException | FormatException e) {
e.printStackTrace();
mTvMessage.setText("Ошибка чтения");
return null;
}
finally {
mProgres.setVisibility(View.GONE);
}
}
}
xml Fragment
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="@dimen/activity_horizontal_margin">
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Чтение тэга NFC"
android:textAppearance="?android:attr/textAppearanceLarge"/>
<ImageView
android:id="@+id/logo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="@dimen/activity_horizontal_margin"
android:src="@drawable/ic_nfc"
android:tint="@color/colorAccent"/>
<ProgressBar
android:id="@+id/progressBarRead"
style="?android:attr/progressBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/tv_message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="@dimen/activity_horizontal_margin"
android:text="Приложите телефон к метке NFC"/>
`enter code here` </LinearLayout>
MainActivity
public class MainActivity extends AppCompatActivity implements Listener,
NFCReadFragment.OnReadDataPass {
private Button mBtRead;
private NFCReadFragment mNfcReadFragment;
public static final String TAG = MainActivity.class.getSimpleName();
private boolean isDialogDisplayed = false;
private boolean isWrite = false;
private NfcAdapter mNfcAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_read);
initViews();
initNFC();
}
private void initViews() {
final Animation animAlpha = AnimationUtils.loadAnimation(this,
R.anim.anim_alfa);
mBtRead = (Button) findViewById(R.id.button);
mBtRead.setOnClickListener(new Button.OnClickListener(){
@Override
public void onClick(View view){
view.startAnimation(animAlpha);
showReadFragment();
}
});
// mBtRead.setOnClickListener(view -> showReadFragment());
}
private void initNFC(){
mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
}
private void showReadFragment() {
mNfcReadFragment = (NFCReadFragment)
getFragmentManager().findFragmentByTag(NFCReadFragment.TAG);
if (mNfcReadFragment == null) {
mNfcReadFragment = NFCReadFragment.newInstance();
}
mNfcReadFragment.show(getFragmentManager(),NFCReadFragment.TAG);
}
@Override
public void onDialogDisplayed() {
isDialogDisplayed = true;
}
@Override
public void onDialogDismissed() {
isDialogDisplayed = false;
isWrite = false;
}
@Override
protected void onResume() {
super.onResume();
IntentFilter tagDetected = new
IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
IntentFilter ndefDetected = new
IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
IntentFilter techDetected = new
IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
IntentFilter[] nfcIntentFilter = new IntentFilter[]{techDetected,tagDetected,ndefDetected};
PendingIntent pendingIntent = PendingIntent.getActivity(
this, 0, new Intent(this,
getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
if(mNfcAdapter!= null)
mNfcAdapter.enableForegroundDispatch(this, pendingIntent,
nfcIntentFilter, null);
}
@Override
protected void onPause() {
super.onPause();
if(mNfcAdapter!= null)
mNfcAdapter.disableForegroundDispatch(this);
}
@Override
protected void onNewIntent(Intent intent) {
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
Log.d(TAG, "onNewIntent: "+intent.getAction());
if(tag != null) {
Toast.makeText(this, getString(R.string.message_tag_detected), Toast.LENGTH_SHORT).show();
Ndef ndef = Ndef.get(tag);
if (isDialogDisplayed) {
mNfcReadFragment = (NFCReadFragment)getFragmentManager().findFragmentByTag(NFCReadFragment.TAG);
mNfcReadFragment.onNfcDetected(ndef);
}
}
}
public void transfToData(byte[][] buf){
Intent intent = new Intent(MainActivity.this, Tabs.class);
intent.putExtra("record_ndef", buf);
startActivity(intent);
}
private byte[][] readFromNFC(Ndef ndef) {
try {
ndef.connect();
NdefMessage ndefMessage = ndef.getNdefMessage();
byte buf[][] = new byte[ndefMessage.getRecords().length][];
//ID[i] = GetId();
//i++;
String f;
for (int i = 0; i < ndefMessage.getRecords().length; i++) {
buf[i] = ndefMessage.getRecords()[i].getPayload();
f = new String(buf[i]);
}
ndef.close();
return buf;
} catch (IOException | FormatException e) {
e.printStackTrace();
return null;
}
}
private String GetId(){
Tag myTag = (Tag) getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG);
String ID = bytesToHexString(myTag.getId());
return ID;
}
private String bytesToHexString(byte[] src){
StringBuilder stringBuilder = new StringBuilder("0x");
if(src == null || src.length <= 0){
return null;
}
char[] buffer = new char[2];
for(int i = 0; i < src.length; i++){
buffer[0] = Character.forDigit((src[i] >>> 4) & 0x0F, 16);
buffer[1] = Character.forDigit(src[i] & 0x0F, 16);
System.out.println(buffer);
stringBuilder.append(buffer);
}
return stringBuilder.toString();
}
@Override
public void onReadDataPass(byte[][] data) {
if(data != null) {
Intent intent = new Intent(this, Tabs.class);
intent.putExtra("record_ndef", data);
startActivity(intent);
}
}
@Override
public void onBackPressed(){
openQuitDialog();
}
private void openQuitDialog(){
AlertDialog.Builder quitDialog = new AlertDialog.Builder(MainActivity.this);
quitDialog.setTitle("Закрыть приложение?");
quitDialog.setPositiveButton("Закрыть", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
System.runFinalization();
System.exit(0);
}
});
quitDialog.setNegativeButton("Отмена", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
});
quitDialog.show();
}
}
在阅读过程中需要显示ProgressBar。
目前，它只在进入第二个活动之前显示。
答案 0 :(得分：0)
只有在阅读NFC后才能获取NFC详细信息后，才会调用 onNfcDetected（）方法。您可以从片段 initViews（）方法中删除 mProgres.setVisibility（View.GONE）; 。
答案 1 :(得分：0)
您不断隐藏进度条：
finally {
mProgres.setVisibility(View.GONE);
}
因为它在每个周期运行。 在代码中创建一些日志以进行验证。我每次将视图设置为GONE时都会添加一些Log.d（），这样我就知道发生了什么。
为什么不在AsyncTask中完成所有工作并调用View.GONE onPostExecute（）？它更干净。
答案 2 :(得分：0)
您可以使用
隐藏进度条mProgres.setVisibility（View.INVISIBLE）;
不要使用GONE ，一旦使用它，接下来就不能使用此ProgressBar。
因此，您的ProgressBar不会显示在procress阅读中。
您可以尝试以下内容：
private void initViews(View view) {
mTvMessage = (TextView) view.findViewById(R.id.tv_message);
mProgres = (ProgressBar) view.findViewById(R.id.progressBarRead);
mProgres.setVisibility(View.INVISIBLE);
}