There is an application that, when it is first launched, downloads data from the server database. For loading I use Volley . Added ProgressBar, so that the user does not look into an empty window.

The ProgressBar is barely moving until Volley requests are executed. Slightly shifted from the original position and all. As I understand it, Volley is asynchronous.

What could be the problem?

UPD. I add the code.

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener { public LinearLayout cartSticker; DbHelper dbHelper; Cursor c; ListView itemsList; GridView itemsGrid; ListView menu; DrawerLayout drawer; Toolbar toolbar; ActionBarDrawerToggle toggle; public Core core; @Override protected void onCreate(Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); setProgressBarIndeterminateVisibility(true); super.onCreate(savedInstanceState); LayoutInflater lInflater = getLayoutInflater(); dbHelper = new DbHelper(this); core = Core.getInstance(); core.setContext(this); core.setHelper(dbHelper); setContentView(R.layout.activity_main); toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); cartSticker = (LinearLayout) findViewById(R.id.cart_items_sticker_wrapper); drawer = (DrawerLayout) findViewById(R.id.drawer_layout); toggle = new android.support.v7.app.ActionBarDrawerToggle( this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); drawer.setDrawerListener(toggle); toggle.syncState(); menu = (ListView) findViewById(R.id.cats_list); menu.addHeaderView(lInflater.inflate(R.layout.cat_list_header, null), null, true); menu.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { VHolder holder = (VHolder) view.getTag(); if (holder == null) { showMainPage(); drawer.closeDrawers(); } else { int catId = holder.id; openCat(catId); } } }); updateCartSticker(dbHelper.getCartItemsCount()); toolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { drawer.openDrawer(Gravity.LEFT); } }); drawer.closeDrawers(); pB = new ProgressBar(getApplicationContext()); } ProgressBar pB; public void showLoader() { AbsListView.LayoutParams lP = new AbsListView.LayoutParams(70, 70); ((LinearLayout) findViewById(R.id.loader_wrapper)).addView(pB, lP); } public void hideLoader() { ((LinearLayout) findViewById(R.id.loader_wrapper)).removeAllViews(); } @Override protected void onStart() { super.onStart(); new DataLoader().execute(""); } private void buildMenu() { String[] from = {"name"}; int[] to = {R.id.name}; c = dbHelper.getCat(); MenuCursorAdapter mca = new MenuCursorAdapter(this, c, 1); menu.setAdapter(mca); } public void showMainPage() { Fragment fr = new MainFragment(); FragmentManager fM = getFragmentManager(); FragmentTransaction fTr = fM.beginTransaction(); fTr.replace(R.id.main_content, fr); fTr.commit(); } public void buildProducts(int catId, int type) { Fragment fragment = new ListFragment(); Bundle args = new Bundle(); args.putInt("catId", catId); args.putInt("type", type); fragment.setArguments(args); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction fTr = fragmentManager.beginTransaction(); fTr.replace(R.id.main_content, fragment); fTr.addToBackStack(null); fTr.commit(); } public void openCat(int id) { Category cat = dbHelper.getCategory(id); toolbar.setTitle(cat.name); buildProducts(id, 0); drawer.closeDrawers(); } public void openCart() { { Fragment fragment = new CartFragment(); Bundle args = new Bundle(); fragment.setArguments(args); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction fTr = fragmentManager.beginTransaction(); fTr.replace(R.id.main_content, fragment); fTr.addToBackStack(null); fTr.commit(); toolbar.setTitle(getResources().getText(R.string.app_cart)); } } public void openProduct(int id) { Fragment fragment = new ProductFragment(); Bundle args = new Bundle(); args.putInt("productId", id); fragment.setArguments(args); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction fTr = fragmentManager.beginTransaction(); fTr.replace(R.id.main_content, fragment); fTr.addToBackStack(null); fTr.commit(); } @Override public void onBackPressed() { DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); if (drawer.isDrawerOpen(GravityCompat.START)) { drawer.closeDrawer(GravityCompat.START); } else { if (getFragmentManager().getBackStackEntryCount() > 0) { getFragmentManager().popBackStack(); } else { super.onBackPressed(); } } } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { if (toggle.onOptionsItemSelected(item)) { return true; } int id = item.getItemId(); if (id == R.id.action_cart) { openCart(); return true; } return super.onOptionsItemSelected(item); } @SuppressWarnings("StatementWithEmptyBody") @Override public boolean onNavigationItemSelected(MenuItem item) { // Handle navigation view item clicks here. int id = item.getItemId(); if (id == R.id.nav_camera) { // Handle the camera action } else if (id == R.id.nav_gallery) { } else if (id == R.id.nav_slideshow) { } else if (id == R.id.nav_manage) { } else if (id == R.id.nav_share) { } else if (id == R.id.nav_send) { } DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); drawer.closeDrawer(GravityCompat.START); return true; } public void loadFromServer() { showLoader(); RequestQueue rQ = Volley.newRequestQueue(this); // Request a string response from the provided URL. StringRequest catsRequest = new StringRequest(Request.Method.GET, Core.catsUrl, new Response.Listener<String>() { @Override public void onResponse(String response) { dbHelper.updateCategories(response); buildMenu(); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { } }); StringRequest prodsRequest = new StringRequest(Request.Method.GET, Core.prodsUrl, new Response.Listener<String>() { @Override public void onResponse(String response) { dbHelper.updateProducts(response); buildMenu(); showMainPage(); SharedPreferences sp = getSharedPreferences("gorillagym_update_data_flag", Context.MODE_PRIVATE); SharedPreferences.Editor spe = sp.edit(); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { } }); rQ.add(catsRequest); rQ.add(prodsRequest); } public void updateFromServer() { String date = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss").format(new Date()); SharedPreferences sp = getSharedPreferences("gorillagym_update_data_flag", Context.MODE_PRIVATE); String lastUpdateDate = sp.getString("last_update_date", date); RequestQueue rQ = Volley.newRequestQueue(this); StringRequest updateRequest = new StringRequest(Request.Method.GET, Core.updateUrl + "&date=" + lastUpdateDate, new Response.Listener<String>() { @Override public void onResponse(String response) { try { JSONObject jObject = new JSONObject(response); boolean status = jObject.getBoolean("status"); String lastTime = jObject.getString("lastTime"); if (status) { dbHelper.updateData(response); SharedPreferences sp = getSharedPreferences("gorillagym_update_data_flag", Context.MODE_PRIVATE); SharedPreferences.Editor spe = sp.edit(); spe.putString("last_update_date", lastTime); spe.apply(); } } catch (Exception e) { } } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { } }); rQ.add(updateRequest); } public void updateData() { SharedPreferences sp = getSharedPreferences("gorillagym_update_data_flag", Context.MODE_PRIVATE); if (sp.getBoolean("first_install", true)) { loadFromServer(); } else { showMainPage(); updateFromServer(); } } public void updateCartSticker(int count) { if (count <= 0) { cartSticker.setVisibility(View.GONE); ((TextView) cartSticker.findViewById(R.id.cart_items_sticker)).setText(""); } else { cartSticker.setVisibility(View.VISIBLE); ((TextView) cartSticker.findViewById(R.id.cart_items_sticker)).setText(String.valueOf(count)); } } public class DataLoader extends AsyncTask<String, Void, Bitmap> { public DataLoader () { } @Override protected void onPreExecute() { super.onPreExecute(); } protected Bitmap doInBackground(String... urls) { updateData(); return null; } protected void onPostExecute(Bitmap result) { } }

}

  • one
    I would give a code snippet at least - fortuna58rus
  • The problem is in your code. This was a demo version of the answer. You will receive the full version by listing your code. - Vladyslav Matviienko 5:58 pm

1 answer 1

I can assume that your Volley is not synchronized enough.

Try to make a test AsyncTask (Test! Use it is a bad idea - there are a lot of problems with turning).

In it, in doInBackground you do the operations you need, and through the publishProgress() update the progressBar state.

If everything goes smoothly, it means that everything happened in your main thread, and you need to think about asynchrony yourself.

  • I just wanted to add an endless progress bar, and hide it after executing queries. Display progress is required. Now I will try AsyncTask to protest, thanks for the advice. - asmproger
  • @asmproger then everything becomes even easier - the endless progress bar is a circle or a line. Therefore, you just need to identify the moment when to show it, and when to hide it. Do not even need to break into portions. - Silento
  • I started to try AsyncTask, and found that the problem is not in the request, but in its processing. JSON comes to me from the server, about 260 items. And I in a cycle disassemble it, and I push in request. This is where the brakes start, and the progress bar does not move. When I remove the processing - everything works fine, and hides. I will understand further. - asmproger