im having a problem when the app is down. the function stop() in the file "my application" save the current Form, but when i try to make a download and i put the app in background task , when try go back to the app , the app is keeping the dialog "loading" forever... i don't know how to finish the current download in background and show the next Form when go back to the app.
the code of "myapplication" file:
private Form current;
public void start() {
if(current != null){
current.show();
return;
}
new StateMachine("/theme");
}
public void stop() {
current = Display.getInstance().getCurrent();
}
Just do something like:
if(current instanceof Dialog) {
current = null;
}
Related
I have a recyclerview set up in xamarin.android as per the code in this link
https://www.appliedcodelog.com/2019/08/reorder-list-items-by-drag-and-drop-in.html
My question is, how can I remember the position of these items when the app is restarted etc. When the user adds items they are inserted at adapter position 0,1,2,3 etc but when they close the app and come back in, it is not always in the same order.
The user can also rearrange by drag and drop so this seems to add even more confusion!
Currently I have the items in the recyclerview being saved by converting the list to Json and loading when the app opens again but as I said, the items aren't always in the same order as before the app was closed.
Can anyone advise the best way to do this? I have tried to add the item name and position number to a list converting to json then trying to insert the item at the saved position index but can't get it to work..
Thanks
Do you want to achieve the result like following GIF?
You can use PreferenceManager to store position of items(Before store data, I will Serialize data) in a recyclerview.
You can override OnPause() method, this method will be executed when application is background or app is killed. So we can store the position and data in this method.Here is code about ReOrderActivity
[Activity(Label = "ReOrderList")]
public class ReOrderActivity : Activity, IOnStartDragListener
{
private ItemTouchHelper _mItemTouchHelper;
public static ObservableCollection<string> ResourceList;
private RecyclerView _resourceReorderRecyclerView;
ReOrderAdapters resourceAdapter;
ISharedPreferences prefs;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.ReOrderLayout);
prefs = PreferenceManager.GetDefaultSharedPreferences(this);
GetCollection();
resourceAdapter = new ReOrderAdapters(ResourceList, this);
// Initialize the recycler view.
_resourceReorderRecyclerView = FindViewById<RecyclerView>(Resource.Id.ResourceReorderRecyclerView);
Button mDone = FindViewById<Button>(Resource.Id.mDone);
mDone.Click += MDone_Click;
_resourceReorderRecyclerView.SetLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.Vertical, false));
_resourceReorderRecyclerView.SetAdapter(resourceAdapter);
_resourceReorderRecyclerView.HasFixedSize = true;
ItemTouchHelper.Callback callback = new SimpleItemTouchHelperCallback(resourceAdapter);
_mItemTouchHelper = new ItemTouchHelper(callback);
_mItemTouchHelper.AttachToRecyclerView(_resourceReorderRecyclerView);
}
protected override void OnPause()
{
base.OnPause();
string ConvertData = JsonConvert.SerializeObject(ResourceList);
ISharedPreferencesEditor editor = prefs.Edit();
editor.PutString("ObservableCollection_ConvertData", ConvertData);
// editor.Commit(); // applies changes synchronously on older APIs
editor.Apply(); // applies changes asynchronously on newer APIs
}
private void MDone_Click(object sender, System.EventArgs e)
{
resourceAdapter.AddItem("Add item");
}
public void OnStartDrag(RecyclerView.ViewHolder viewHolder)
{
_mItemTouchHelper.StartDrag(viewHolder);
}
//Added sample data record here
public void GetCollection()
{
//ISharedPreferencesEditor editor = prefs.Edit();
//editor.PutString("ObservableCollection_ConvertData", "");
//editor.Apply();
string ConvertData = prefs.GetString("ObservableCollection_ConvertData","");
if(string.IsNullOrEmpty(ConvertData))
{
ResourceList = new ObservableCollection<string>();
ResourceList.Add("OnPause()");
ResourceList.Add("OnStart()");
ResourceList.Add("OnCreate()");
}
else
{
ResourceList= JsonConvert.DeserializeObject<ObservableCollection<string>>(ConvertData);
}
//var or= ResourceList.ToString();
}
}
}
You can download my demo
https://drive.google.com/file/d/1mQTKf3rlcIVnf2N97amrqtnrSCRk-8ZW/view?usp=sharing
I just want to be able to display a list of contacts (without even communicating to a server) just the way it is displayed on the "Contacts" native app on the phone.
I have like 1500 contacts and when I try to load the recycler view, all items at once, it lags a lot 2 - 3 seconds.
I've achieved loading more items but with a loading bar and thats not what I want.
I've already tried Threads, Executors, postOnUIThread(), handler.post() and even AsyncTask -> Override -> doOnBackground. Nothing works.
private class CustomTask extends AsyncTask<Void, Void, Void> {
int inserted;
#Override
protected Void doInBackground(Void... param) {
//Do some work
try {
lcf.getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
((BaseActivity) lcf.getActivity()).showProgressDialog();
}
});
int currentSize = contactsLoaded.size();
for (inserted = 0; inserted < lcf.getController().getContacts().size() && contactsLoaded.size() < lcf.getController().getContacts().size(); inserted++) {
contactsLoaded.add(lcf.getController().getContacts().get(currentSize + inserted));
notifyItemRangeInserted(contactsLoaded.size() - 1, inserted);
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void param) {
//Print Toast or open dialog
//notifyItemRangeInserted(contactsLoaded.size() - 1, 0);
if(!lcf.getController().isSelectedAffiliated()){
lcf.disclaimerLayout.setVisibility(View.VISIBLE);
}else{
lcf.disclaimerLayout.setVisibility(View.GONE);
}
lcf.isLoading=false;
((BaseActivity) lcf.getActivity()).hideProgressDialog();
}
}
That code lives within my adapter, "lcf" is a reference to the fragment. If I use the already loaded list saved on the controller (that I get from the fragment reference) and then just call notifyDataSetChanged() it LAGS like hell. So with this CustomTask I tried to load every item and notify it one by one to a Background task hoping it would make the items pop up quickly and sequentially without interfereing with the UI thread to not freeze the screen. It doesn't work. I am out of options now. I've tried everything.
I want to show some pages in the first time app is installed, and the next time when I open the app show some other pages.
I tried this code
protected override void OnStart()
{
if (Application.Current.Properties.ContainsKey("id"))
{
MainPage = new NavigationPage(new Page2());
}
else
{
Application.Current.Properties["id"] = 2;
MainPage = new NavigationPage(new Page1());
}
}
The values in the Properties dictionary are only stored when the app goes to sleep
For a cross-platform approach, you can use the Settings Plugin
Then you can create a boolean property, for example, DidOpenOnce, and if it is false, show your initial welcome page or whatever. Then afterwards, set it to true.
protected void checkApplicationInstallState()
{
//retreive
var prefs = Application.Context.GetSharedPreferences("MyApp", FileCreationMode.Private);
var somePref = prefs.GetBool("IsApplicationOpenedForOnce", null);
if (!somePref) {
// Your Application is opened for the very first time. Now change the value to true as you have now opened the app so next time opening this application should get a true value.
var prefEditor = prefs.Edit();
prefEditor.PutBool(true, "IsApplicationOpenedForOnce");
prefEditor.Commit();
}
}
public MainPage()
{
InitializeComponent();
if (Application.Current.Properties.ContainsKey("FirstUse"))
{
//Do things when it's NOT the first use...
loadinit();
}
else
{
Application.Current.Properties["FirstUse"] = false;
//Do things when it IS the first use...
}
}
public async void loadinit()
{
await Navigation.PushAsync(new LoadPage());
}
I have a main activity with 6 buttons. Every button starts a new activity.
The program worked well but after that I changed some graphical attributes and made some changes in the theme a mistake occurred . I should press back button 3 times to return from an activity or exit from the main activity. Any suggestions?
btn_weeks.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View arg0, MotionEvent arg1) {
Intent i = new Intent(MainActivity.this, Weeks.class);
startActivity(i);
return false;
}
});
Buttons should implements View.OnClickListener and not OnTouchListener.
I am creating an Android activity and starting a service from this activity using the following code. Now I want to display text "Hello user" from this service to screen, meaning service should trigger this display. I could use Toast.maketext.show but the display will disappear after couple of seconds.
new Thread(new Runnable() {
#Override
public void run() {
startAdapterIntent.setAction("START_ADAPTER");
startService(startAdapterIntent);
System.out.println("Thread2: Adapter Service started.");
}
}).start();
How do I do that?
I tried to use this link:
Making changes to Main Activity UI from thread in Service
and its (probably) parent link
http://developer.android.com/reference/android/app/Service.html
section "Remote Messenger Service Sample"
While using this second link, the onServiceConnected part of ServiceConnection doesn't seem to be working? Please help. Thank you.
From within your service you should create a handler that can be triggered by a timer task, the handler should be the one directly responsible of doing the communication with the currently active UI thread..an example would be
long delay = 3000;
long period = 3000;
TimerTask mDoTask = new TimerTask() {
#Override
public void run() {
xHandler.sendMessage(Message.obtain(xHandler, SOME_OPERATION));
}
};
mT.scheduleAtFixedRate(mDoTask, delay, period);
Handler xHandler=new Handler(){
#Override
public void handleMessage(Message message){
switch (message.what){
case SOME_OPERATION:
YourMethod();// in this method you can display your text
break;
}
}
};