displaying a counter in xamarin - mono

I am trying to display a counter but it is not working here is my code:
protected void t_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
EditText v2 = (EditText)FindViewById(Resource.Id.editText5);
counter1--;
if (counter1 <= 0) {
counter1 = 59;
timer1--;
}
if (timer1 <= 0) {
t.Stop ();
}
try{
v2.Text = timer1+ ":"+ counter1;
}
catch( Exception e8)
{
AlertDialog.Builder builder = new AlertDialog.Builder (this);
builder.SetMessage (e8.Message);
builder.Create().Show();
}
}
` I get this error : e8.Message "Only the original thread that created a view hierarchy can touch its views." string
how can i fix this ?

Invoke your code to the UI thread instead.

Related

Countinouly decrease the value on long click in recylerview adapter class

Below is the code session. please check and solve my issue.
holder.outer_qty.setOnLongClickListener(new View.OnLongClickListener() {
private Handler mHandler = new Handler();
private Runnable incrementRunnable = new Runnable() {
#Override public void run() {
mHandler.removeCallbacks(incrementRunnable);
if (holder.outer_qty.isPressed()) {
if (holder.outer_count > 1) {
Fragment_cataloguesall.mselected_update = 1;
holder.outer_count = holder.outer_count - 1;
holder.Total_outerQTY = holder.outerqntyValue * holder.outer_count;
holder.Total_qty.setText(Integer.toString(holder.Total_outerQTY));
Fragment_cataloguesall.dbcustom_list_vertical.notifyDataSetChanged();
helper.update_allpro(holder.productCode.getText().toString(), holder.plus_sign.getText().toString(), holder.outer_qty.getText().toString(), holder.Total_qty.getText().toString(), String.valueOf(holder.outer_count), "0");
holder.outer_count++;
dbList.clear();
mFilteredList.clear();
dbList = helper.GetProductData(Fragment_cataloguesall.CatCode, Fragment_cataloguesall.SubcatCode, "", Filter_screen);
mFilteredList = dbList;
selectedCard = dbList;
} else {}
mHandler.postDelayed(incrementRunnable, 1);
}
}
};
#Override
public boolean onLongClick(View view) {
mHandler.postDelayed(incrementRunnable, 1);
return true;
}
});
How to solve this issue please explain or help me to solve it?

Implement Infinite scroll with ViewModel And Retrofit in recyclerview

Before adding viewmodel & livedata , i successfully implemented infinity scroll with retrofit. But after adding viewmodel & livedata with Retrofit, My can't update recyclerview with new data call or viewmodel observer not update the list.
I simply want to infinite scrolling as my code does before. I add a global variable to reuse next page token. Am i missing anything or any sample to implement infinite recyclerview with viewmodel & retrofit will be awesome.
public static String NEXT_PAGE_URL = null;
I coded like that.
My Activity -> PlaceListActivity
placeRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
LogMe.d(tag, "onScrollStateChanged:: " + "called");
// check scrolling started or not
if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
isScrolling = true;
}
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
LogMe.d(tag, "onScrolled:: " + "called");
super.onScrolled(recyclerView, dx, dy);
currentItem = layoutManager.getChildCount();
totalItems = layoutManager.getItemCount();
scrolledOutItems = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstVisibleItemPosition();
LogMe.d(tag, "currentItem:: " + currentItem);
LogMe.d(tag, "totalItems:: " + totalItems);
LogMe.d(tag, "scrolledOutItems:: " + scrolledOutItems);
if (isScrolling && (currentItem + scrolledOutItems == totalItems)) {
LogMe.d(tag, "view:: " + "finished");
isScrolling = false;
if (ApplicationData.NEXT_PAGE_URL != null) {
LogMe.d(tag, "place adding:: " + " onScrolled called");
ll_loading_more.setVisibility(View.VISIBLE);
// todo: call web api here
callDataFromLocationAPi(type, ApplicationData.NEXT_PAGE_URL, currentLatLng);
} else {
LogMe.d(tag, "next_page_url:: " + " is null");
}
}
}
});
private void callDataFromLocationAPi(String type, String next_page_url, LatLng latLng) {
if (Connectivity.isConnected(activity)) {
showProgressDialog();
model.getNearestPlaces(type, next_page_url, latLng).
observe(activity, new Observer<List<PlaceDetails>>() {
#Override
public void onChanged(#Nullable List<PlaceDetails> placeDetails) {
ll_loading_more.setVisibility(View.GONE);
LogMe.i(tag, "callDataFromLocationAPi: onChanged called !");
hideProgressDialog();
if (placeDetails != null) {
placeDetailsList = placeDetails;
placeListAdapter.setPlaceList(placeDetails);
}
}
});
} else {
showAlertForInternet(activity);
}
}
In PlaceViewModel
public class PlaceViewModel extends AndroidViewModel {
//this is the data that we will fetch asynchronously
private MutableLiveData<List<PlaceDetails>> placeList;
private PlaceRepository placeRepository;
private String tag = getClass().getName();
public PlaceViewModel(Application application) {
super(application);
placeRepository = new PlaceRepository(application);
}
//we will call this method to get the data
public MutableLiveData<List<PlaceDetails>> getNearestPlaces(String type,
String next_page_token,
LatLng latLng) {
//if the list is null
if (placeList == null) {
placeList = new MutableLiveData<>();
//we will load it asynchronously from server in this method
//loadPlaces(type, next_page_token, latLng);
placeList = placeRepository.getNearestPlacesFromAPI(type, next_page_token, latLng);
}
//finally we will return the list
return placeList;
}
}
In my PlaceRepository.java looks
public class PlaceRepository {
private static final Migration MIGRATION_1_2 = new Migration(1, 2) {
#Override
public void migrate(SupportSQLiteDatabase database) {
// Since we didn't alter the table, there's nothing else to do here.
}
};
private PlaceDatabase placeDatabase;
private CurrentLocation currentLocation = null;
private String tag = getClass().getName();
//this is the data that we will fetch asynchronously
private MutableLiveData<List<PlaceDetails>> placeList;
public PlaceRepository(Context context) {
placeDatabase = PlaceDatabase.getDatabase(context);
//addMigrations(MIGRATION_1_2)
placeList =
new MutableLiveData<>();
}
public MutableLiveData<List<PlaceDetails>> getNearestPlacesFromAPI(String type, final String next_page_token, LatLng latLng) {
List<PlaceDetails> placeDetailsList = new ArrayList<>();
try {
ApiInterface apiService = ApiClient.getClient().create(ApiInterface.class);
Call<Example> call = apiService.getNearbyPlaces(type,
latLng.latitude + "," +
latLng.longitude, ApplicationData.PROXIMITY_RADIUS,
ApplicationData.PLACE_API_KEY, next_page_token);
call.enqueue(new Callback<Example>() {
#Override
public void onResponse(Call<Example> call, Response<Example> response) {
try {
Example example = response.body();
ApplicationData.NEXT_PAGE_URL = example.getNextPageToken();
// next_page_url = example.getNextPageToken();
LogMe.i(tag, "next_page_url:" + ApplicationData.NEXT_PAGE_URL);
if (example.getStatus().equals("OK")) {
LogMe.i("getNearbyPlaces::", " --- " + response.toString() +
response.message() + response.body().toString());
// This loop will go through all the results and add marker on each location.
for (int i = 0; i < example.getResults().size(); i++) {
Double lat = example.getResults().get(i).getGeometry().getLocation().getLat();
Double lng = example.getResults().get(i).getGeometry().getLocation().getLng();
String placeName = example.getResults().get(i).getName();
String vicinity = example.getResults().get(i).getVicinity();
String icon = example.getResults().get(i).getIcon();
String place_id = example.getResults().get(i).getPlaceId();
PlaceDetails placeDetails = new PlaceDetails();
if (example.getResults().get(i).getRating() != null) {
Double rating = example.getResults().get(i).getRating();
placeDetails.setRating(rating);
}
//List<Photo> photoReference = example.getResults().
// get(i).getPhotos();
placeDetails.setName(placeName);
placeDetails.setAddress(vicinity);
placeDetails.setLatitude(lat);
placeDetails.setLongitude(lng);
placeDetails.setIcon(icon);
placeDetails.setPlace_id(place_id);
//placeDetails.setPlace_type(place_type_title);
double value = ApplicationData.
DISTANCE_OF_TWO_LOCATION_IN_KM(latLng.latitude, latLng.longitude, lat, lng);
//new DecimalFormat("##.##").format(value);
placeDetails.setDistance(new DecimalFormat("##.##").format(value));
String ph = "";
if (example.getResults().
get(i).getPhotos() != null) {
try {
List<Photo> photos = example.getResults().
get(i).getPhotos();
//JSONArray array = new JSONArray(example.getResults().
//get(i).getPhotos());
//JSONObject jsonObj = new JSONObject(array.toString());
//ph = jsonObj.getString("photo_reference");
ph = photos.get(0).getPhotoReference();
//LogMe.i(tag, "\n" + ph);
} catch (Exception e) {
e.printStackTrace();
//placeDetails.setPicture_reference(ph);
//PLACE_DETAILS_LIST.add(placeDetails);
//LogMe.i(tag, "#### Exception Occureed ####");
ph = "";
//continue;
}
}
placeDetails.setPicture_reference(ph);
placeDetailsList.add(placeDetails);
placeList.postValue(placeDetailsList);
}
} else {
}
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public void onFailure(Call<Example> call, Throwable t) {
Log.e("onFailure", t.toString());
}
});
} catch (RuntimeException e) {
//hideProgressDialog();
Log.d("onResponse", "RuntimeException is an error");
e.printStackTrace();
} catch (Exception e) {
Log.d("onResponse", "Exception is an error");
}
return placeList;
}
}
I precise code due to question simplicity.
Though you already use android-jetpack, take a look at Paging library. It's specially designed for building infinite lists using RecyclerView.
Based on your source code, I'd say that you need PageKeyedDataSource, here is some example which includes info about how to implement PageKeyedDataSource -
7 steps to implement Paging library in Android
If talking about cons of this approach:
You don't need anymore to observe list scrolling (library doing it for you), you just need to specify your page size in the next way:
PagedList.Config myPagingConfig = new PagedList.Config.Builder()
.setPageSize(50)
.build();
From documentation:
Page size: The number of items in each page.
Your code will be more clear, you'll get rid of your RecyclerView.OnScrollListener
ViewModel code will be shorter, it's will provide only PagedList:
#NonNull
LiveData<PagedList<ReviewSection>> getReviewsLiveData() {
return reviewsLiveData;
}

Accessing activity 2 while foreground is activity 1 (either using OOP or Service in XAMARIN)

i code this from a tutorial for locating your location (but I already made some changes)
using Android.App;
using Android.Widget;
using Android.OS;
using Android.Locations;
using System.Collections.Generic;
using Android.Util;
using System.Linq;
using Java.Lang;
using System.Threading.Tasks;
using System;
using Android.Views;
using Android.Content;
namespace LocatorApp
{
[Activity(Label = "Locator", MainLauncher = true, Icon = "#drawable/locator_ico")]
public class LocatorApp : Activity, ILocationListener
{
static readonly string TAG = "X:" + typeof(LocatorApp).Name;
TextView _addressText;
Location _currentLocation;
LocationManager _locationManager;
Address address;
string _locationProvider;
TextView _locationText;
private double latitude = 0;
private double longitude = 0;
public Location getCurrentLocation() { return _currentLocation; }
public double getLatitude() { return latitude; }
public double getLongitude() { return longitude; }
public Address getAddress() { return address; }
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
_addressText = FindViewById<TextView>(Resource.Id.address_text);
_locationText = FindViewById<TextView>(Resource.Id.location_text);
FindViewById<TextView>(Resource.Id.get_address_button).Click += AddressButton_OnClick;
InitializeLocationManager();
}
public void InitializeLocationManager()
{
_locationManager = (LocationManager)GetSystemService(LocationService);
Criteria criteriaForLocationService = new Criteria
{
Accuracy = Accuracy.Coarse,
PowerRequirement = Power.Medium
};
IList<string> acceptableLocationProviders = _locationManager.GetProviders(criteriaForLocationService, true);
if (acceptableLocationProviders.Any())
{
_locationProvider = acceptableLocationProviders.First();
}
else
{
_locationProvider = string.Empty;
}
Log.Debug(TAG, "Using " + _locationProvider + ".");
}
async void AddressButton_OnClick(object sender, EventArgs eventArgs)
{
if (_currentLocation == null)
{
Toast.MakeText(this, "Still waiting for location.", ToastLength.Short).Show();
}
else
{
try
{
var geoUri = Android.Net.Uri.Parse("geo:" + _currentLocation.Latitude + "," + _currentLocation.Longitude);
var mapIntent = new Intent(Intent.ActionView, geoUri);
StartActivity(mapIntent);
}
catch (System.Exception e)
{
Toast.MakeText(this, "Sorry, there is a problem with geomapping.", ToastLength.Short).Show();
}
}
}
async Task<Address> ReverseGeocodeCurrentLocation()
{
try
{
Geocoder geocoder = new Geocoder(this);
IList<Address> addressList =
await geocoder.GetFromLocationAsync(_currentLocation.Latitude, _currentLocation.Longitude, 10);
Address address = addressList.FirstOrDefault();
return address;
}
catch (System.Exception e)
{
throw;
}
return null;
}
void DisplayAddress(Address address)
{
if (address != null)
{
StringBuilder deviceAddress = new StringBuilder();
for (int i = 0; i < address.MaxAddressLineIndex; i++)
{
deviceAddress.Append(address.GetAddressLine(i));
}
// Remove the last comma from the end of the address.
_addressText.Text = "Address: "+deviceAddress.ToString();
}
else
{
_addressText.Text = "Unable to determine the address. Try again in a few minutes.";
}
}
public async void OnLocationChanged(Location location)
{
Toast.MakeText(this, "Location changed.", ToastLength.Short).Show();
_currentLocation = location;
if (_currentLocation == null)
{
_locationText.Text = "Unable to determine your location. Try again in a short while.";
}
else
{
try
{
_locationText.Text = "Location: " + string.Format("{0:f6},{1:f6}", _currentLocation.Latitude, _currentLocation.Longitude);
Address address = await ReverseGeocodeCurrentLocation();
DisplayAddress(address);
var nMgr = (NotificationManager)GetSystemService(NotificationService);
var notification = new Notification(Resource.Drawable.Icon, "Message from LocatorApp");
var pendingIntent = PendingIntent.GetActivity(this, 0, new Intent(this, typeof(LocatorApp)), 0);
notification.SetLatestEventInfo(this, "LocatorApp", "Location changed!", pendingIntent);
nMgr.Notify(0, notification);
}
catch (Java.Lang.Exception e)
{
_addressText.Text = "Unable to determine the address. Try again in a few minutes.";
Toast.MakeText(this, "Error Occured On Geocoder!", ToastLength.Short).Show();
Log.Error(TAG, e.Message);
}
}
}
public void OnProviderDisabled(string provider) { }
public void OnProviderEnabled(string provider) { }
public void OnStatusChanged(string provider, Availability status, Bundle extras) { }
protected override void OnResume()
{
base.OnResume();
if (_locationManager.IsProviderEnabled(_locationProvider))
{
_locationManager.RequestLocationUpdates(_locationProvider, 100, 0, this);
Toast.MakeText(this, _locationProvider.ToString(), ToastLength.Short).Show();
}
else
{
Toast.MakeText(this, "There is a problem with "+_locationProvider.ToString()+" provider.", ToastLength.Short).Show();
}
}
protected override void OnPause()
{
base.OnPause();
_locationManager.RemoveUpdates(this);
}
}
}
(i'm just having my experiment)
what I want is to run activity B while foreground is in activity A, just like a basic OOP . but my problem is, I don't know how to make it run. I can't also jump to activity B since it has an oncreate method. I instantiated it and can get the variables values but they are null (seems there is no process happened) . What can be a best solution for this.
note: I am currently looking how to use service for background processing but also i don't know how to run this code after I typed it from a tutorial :( there is only a tutorial for creating a service part but no tutorial for buttons to access it :(
using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Util;
using System.Threading;
namespace LocatorApp
{
[Service]
class SimpleService : Service
{
static readonly string TAG = "X:" + typeof(SimpleService).Name;
static readonly int TimerWait = 4000;
Timer _timer;
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
Log.Debug(TAG, "OnStartCommand called at {2}, flags={0}, startid={1}", flags, startId, DateTime.UtcNow);
_timer = new Timer(o => { Log.Debug(TAG, "Hello from SimpleService. {0}", DateTime.UtcNow); },
null,
0,
TimerWait);
return StartCommandResult.NotSticky;
}
public override void OnDestroy()
{
base.OnDestroy();
_timer.Dispose();
_timer = null;
Log.Debug(TAG, "SimpleService destroyed at {0}.", DateTime.UtcNow);
}
public override IBinder OnBind(Intent intent)
{
// This example isn't of a bound service, so we just return NULL.
return null;
}
}
}
I want to know both (OOP way and service way) since not at all time we are required to use the service.
what I want is to run activity B while foreground is in activity A, just like a basic OOP . but my problem is, I don't know how to make it run. I can't also jump to activity B since it has an oncreate method.
You can call Context.StartActivity inside your Activity with following codes:
StartActivity(new Android.Content.Intent(this, typeof(ActivityB)));
And StartActivity will call OnCreate method in ActivityB to create a new instance of ActivityB.
For details about Starting Activities, please refer to Starting Activities and Getting Results.
I am currently looking how to use service for background processing but also i don't know how to run this code after I typed it from a tutorial :( there is only a tutorial for creating a service part but no tutorial for buttons to access it :(
Similar like Activity Context.StartService offers a way to start a Service:
StartService (new Intent (this, typeof(DemoService)));
This will call the OnStartCommand method inside your Service class.
For details about usage of Service, please refer to Implementing a Service.

give delay in showing the controls

I would like to add the button controls in a timely manner.
That means, after the shell opened, it should start placing the buttons one by one
in a 1 second delay. I wrote the program,however it does not work. all the buttons
are visible only after all the controls are placed. Some kind of refresh issue I guess.
Following is my code.
public class DelayAddingComponentsExample {
public static void main(String[] args) {
Display display = new Display();
final Shell shell = new Shell(display);
shell.setSize(200, 200);
shell.setLayout(new FillLayout(SWT.VERTICAL));
addAutomatically(shell);
// removeAutomatically(shell);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
public static void addAutomatically(final Shell shell) {
for (int i = 0; i < 5; i++) {
final Button button = new Button(shell, SWT.NONE);
button.setText("Button" + i);
button.setVisible(false);
}
shell.getDisplay().timerExec(0, new Runnable() {
#Override
public void run() {
for (int i = 0; i < 5; i++) {
try {
Thread.sleep(500);
final Button button = new Button(shell, SWT.NONE);
button.setText("Button" + i);
button.setVisible(true);
shell.pack();
shell.layout(true);
shell.redraw();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
}
public static void removeAutomatically(final Shell shell) {
for (int i = 0; i < 5; i++) {
final Button button = new Button(shell, SWT.NONE);
button.setText("Button" + i);
shell.layout(true);
}
shell.getDisplay().timerExec(0, new Runnable() {
#Override
public void run() {
Control[] controls = shell.getChildren();
for (Control control : controls) {
try {
Thread.sleep(500);
control.dispose();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
}
}
The Runnable given to timerExec runs in the UI thread. So the Thread.sleep calls you are making are blocking the UI thread - it is vital that you never block this thread. Never call Thread.sleep in the UI thread.
You must do each step using a separate timeExec call and use the delay parameter of the timerExec call to specify how long to wait.
So
shell.getDisplay().timerExec(500, new Runnable() {
#Override
public void run()
{
// TODO code for the first button only
// Schedule next update
shell.getDisplay().timerExec(500, .... code for second button);
}
});
Runs the Runnable after 500 millseconds, the Runnable should just do the first step and then call timerExec again to schedule the next step.

How to add a list of UIelement in Windows Phone

I want to create a page with dynamic control in windows phone.
While doing this I also want to show a progress bar
Below is my code
protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
base.OnNavigatedTo(e);
progressstackPanel.Visibility = Visibility.Visible;//progress bar
formScreen = this;
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
if (!isfst)
{
DrawScreen();
}
else
{
//xTitlePanel is only stack panel in my xaml with vertical orientation
xTitlePanel.UpdateLayout();
}
isfst = true;
progressstackPanel.Visibility = Visibility.Collapsed;
});
}
//Code of DrawScreen which is adding control to my stack panels
private void DrawScreen()
{
if (frm_getset.ChildList != null)
{
String[] arr = frm_getset.ChildList.Split(',');
xTitlePanel.Children.Clear();
PrepareControls prepcontrol = new PrepareControls();
foreach (AttributeGetSet a in _Attribute)
{
//this will return a stackpanel containing
// button/textbox etc.depending on a
StackPanel sp = prepcontrol.getControl(i, a.Label, a, formScreen);
try
{
xTitlePanel.Children.Add(sp);
///Here I get a eception only one control is added first one
/// for anyone it is getting a exception Argument
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}
i += 1;
}
The system is adding only one control and when ever it try to execute xTitlePanel.Children.Add(sp); it will get an exception.
I solved the problem ,"xTitlePanel" is a StackPanel I created in my XAML. I found you can not add more that one element from Dispatcher to a control crated on xaml. Like that. so I have to create local stack and add controls to the that local stack panel then and after complete I add the local stack panel to xTitlePanel. NOW my code looks like below
filteredList = new List<FormGetSet>();
if (frm_getset.ChildList != null)
{
String[] arr = frm_getset.ChildList.Split(',');
foreach (String x in arr)
{
filteredList.Add(_template.list_fromgetset.Where(p => p.FormID.Contains(x.Trim())).ToList()[0]);
}
}
xTbox_FormNameHeader.Text = frm_getset.NAME;
_Attribute = new List<AttributeGetSet>();
_Attribute = frm_getset.list_attributegetset;
xTitlePanel.Children.Clear();
StackPanel spPanel = new StackPanel();
spPanel.Orientation = System.Windows.Controls.Orientation.Vertical;
spPanel.Background = new SolidColorBrush(Colors.Transparent);
//xTitlePanel.Children.Add(PrepareControls.getControl(1, "LABEL", "16"));
int i = 1;
// List<AttributeGetSet> _Attribute2 = new List<AttributeGetSet>();
foreach (AttributeGetSet a in _Attribute)
{
PrepareControls prepcontrol = new PrepareControls();
StackPanel sp= prepcontrol.getControl(i, a.Label, a, this);
try
{
spPanel.Children.Add(sp);
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}
//xTitlePanel.Background = new SolidColorBrush(Colors.White);
//_Attribute2.Add(a);
i += 1;
}
xTitlePanel.Children.Add(spPanel);