android

[Solved] how to show and hide imageview inside recyclerView

by

You need just add field in your adapter where you will save currently active item. Then call notifyDataSetChanged. Also you should update your onBindViewHolder like this: private int currentPosition = -1; @Override public void onBindViewHolder(@NonNull MyViewHolder holder, int position) { holder.textView.setText(items.get(position)); if (currentPosition == position) { holder.img1.setVisibility(View.INVISIBLE); holder.img2.setVisibility(View.VISIBLE); } else { holder.img1.setVisibility(View.VISIBLE); holder.img2.setVisibility(View.INVISIBLE); } } … Read more

[Solved] Null pointer exception on button send [closed]

by

Just write your if loop after declaration of your all the views in your onCreate() as below: @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); buttonSend = (Button) findViewById(R.id.buttonSend); textTo = (EditText) findViewById(R.id.editTextSendTo); textSubject = (EditText) findViewById(R.id.editTextName); textMessageContact = (EditText) findViewById(R.id.editTextContact); textMessageEmail = (EditText) findViewById(R.id.editTextEmail); textMessageAmount = (EditText) findViewById(R.id.editTextAmount); spinner = (Spinner) findViewById(R.id.spinner); buttonSend.setOnClickListener(new OnClickListener() … Read more

[Solved] setAdapter not recognize in android studio [duplicate]

by

Replace ViewPager.setAdapter(… with viewPager.setAdapter(… ViewPager (with a capital letter) is a class name and by using it here, you are trying to access the static method of that class. There is no static method setAdapter and hence the error. For readability, replace viewPager with pager. It will make it easier for you to avoid such … Read more

[Solved] Can i porposely corrupt a file through Java programming ? Also is it possible to scramble a file contents ?

by

A simple RandomAccessFile scrambler would be this: private static final String READ_WRITE = “rw”; private static final Random random = new Random(); public static void scramble(String filePath, int scrambledByteCount) throws IOException{ RandomAccessFile file = new RandomAccessFile(filePath, READ_WRITE); long fileLength = file.getLength(); for(int count = 0; count < scrambledByteCount; count++) { long nextPosition = random.nextLong(fileLength-1); file.seek(nextPosition); … Read more

[Solved] Retrofit 2 response body is empty or Model class is wrong. Cannot get JSON data it gives an Exception: Expected BEGIN_ARRAY but was BEGIN_OBJECT

by

your model is wrong it should look like this pseudo code public Response{ String status; int count; List<Category> categories; 3 solved Retrofit 2 response body is empty or Model class is wrong. Cannot get JSON data it gives an Exception: Expected BEGIN_ARRAY but was BEGIN_OBJECT

[Solved] Creating Chat App with MySql, php ,w/o GCM

by

Take a look at ajax technology, you can build a full web-based chat system, and use Javascript interface to communicate with your app, so that you can notify your app user there is a new message. BTW, you can modify your question title like Creating Chat App with MySql, php, w/o GCM 9 solved Creating … Read more

[Solved] Shared Preferences saving an int?

by

The Android Developers documentation is an excellent place to start with any question like this. SharedPreferences can be found here. SharedPreferences is a simple Key-Value pair storage, so if you put an int into your shared preferences as with the key “high score”, then in the future, if you want to get that int, you … Read more

[Solved] How to remove notifications when touched? [duplicate]

by

Using flags notification.flags = Notification.FLAG_AUTO_CANCEL; Using Notification builder NotificationCompat.Builder builder = new NotificationCompat.Builder(context); builder.setAutoCancel(true); Using Notification Manager notificationManager.cancel(NOTIFICATION_ID); for API level 18 and above @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2) public class MyNotificationListenerService extends NotificationListenerService {…} … private void clearNotificationExample(StatusBarNotification sbn) { myNotificationListenerService.cancelNotification(sbn.getPackageName(), sbn.getTag(), sbn.getId()); } 2 solved How to remove notifications when touched? [duplicate]

[Solved] Android Export Cropping When XXHDPI Taken as Baseline 100% In Photoshop Then How to crop means size of XHDPI, HDPI, MDPI, LDPI

by

I’m not sure, but don’t you need the resolutions of the images? If so, may I link you to Android Developer support? You can get a lot of information here: A set of six generalized densities: ldpi (low) ~120dpi mdpi (medium) ~160dpi hdpi (high) ~240dpi xhdpi (extra-high) ~320dpi xxhdpi (extra-extra-high) ~480dpi xxxhdpi (extra-extra-extra-high) ~640dpi To … Read more