How to update refresh specific item in RecyclerView

Question

I m trying to refresh specific item in RecyclerView   Story  Whenever user clicks on item  it shows AlertDialog  User can type some text by clicking ok button  I want to show this text in this item and show invisible ImageView - declared in XML and adapter ViewHolder -  I used this function in AlertDialog Positive Button to update the item   private void updateListItem int position      View view   layoutManager findViewByPosition position     ImageView medicineSelected    ImageView  view findViewById R id medicine selected     medicineSelected setVisibility View VISIBLE     TextView orderQuantity    TextView  view findViewById R id order quantity     orderQuantity setVisibility View VISIBLE     orderQuantity setText quantity     packet added        medicinesArrayAdapter notifyItemChanged position       But this code not only changes the itemView at passed position  but also changes some of other itemView s  as well   How should I change specific itemView correctly by clicking on it

User · Answer

if you are creating one object and adding it to the list that you use in your adapter   when you change one element of your list in the adapter all of your other items change too  in other words its all about references and your list doesn t hold separate copies of that single object

User · Answer

You can use the notifyItemChanged int position  method from the RecyclerView Adapter class  From the documentation      Notify any registered observers that the item at position has changed    Equivalent to calling notifyItemChanged position  null         This is an item change event  not a structural change event  It   indicates that any reflection of the data at position is out of date   and should be updated  The item at position retains the same identity    As you already have the position  it should work for you

User · Answer

I think I have an Idea on how to deal with this  Updating is the same as deleting and replacing at the exact position  So I first remove the item from that position using the code below   public void removeItem int position       mData remove position       notifyItemRemoved position       notifyItemRangeChanged position  mData size         and then I would add the item at that particular position as shown below   public void addItem int position  Landscape landscape       mData add position  landscape       notifyItemInserted position       notifyItemRangeChanged position  mData size         I m trying to implement this now  I would give you a feedback when I m through

User · Answer

A way that has worked for me personally  is using the recyclerview s adapter methods to deal with changes in it s items   It would go in a way similar to this  create a method in your custom recycler s view somewhat like this   public void modifyItem final int position  final Model model        mainModel set position  model       notifyItemChanged position

User · Answer

That s also my last problem  Here my solution  I use data Model and adapter for my RecyclerView     Firstly  register your new data to your model    DataModel detail   new DataModel id  name  sat  image       after that  use set to replace old value with the new one    int index   4   mData set index  detail       finally  refresh your adapter    if adapter  null      adapter notifyItemChanged index

User · Answer

you just have to add following code in alert dialog box on save click             recyclerData add position  updateText getText   toString               recyclerAdapter notifyItemChanged position

User · Answer

Add the changed text to your model data list  mdata get position  setSuborderStatusId  5    mdata get position  setSuborderStatus  cancelled    notifyItemChanged position

User · Answer

The problem is RecyclerView Adatper does not provide any methods that return the index of element  public abstract static class Adapter lt VH extends ViewHolder gt               returns index of the given element in adapter  return -1 if not exist         public int indexOf Object elem       My workaround is to create a map instance for  element  position s  public class FriendAdapter extends RecyclerView Adapter lt MyViewHolder gt      private Map lt Friend  Integer gt  posMap     private List lt Friend gt  friends     public FriendAdapter List lt Friend gt  friends         this friends   new ArrayList lt  gt  friends       this posMap   new HashMap lt  gt         for int i   0  i  lt  this friends size    i            posMap put this friends get i   i                public int indexOf Friend friend        Integer position   this posMap get elem       return position    null   -1   position           skip other methods in class Adapter      the element type here class Friend  should implements hashCode   and equals   because it is key in hashmap    when an element changed     void someMethod         Friend friend            friend setPhoneNumber  xxxxx         int position   friendAdapter indexOf friend       friendAdapter notifyItemChanged position          It is good to define an helper method  public class FriendAdapter extends extends RecyclerView Adapter lt MyViewHolder gt       public void friendUpdated Friend friend        int position   this indexOf friend       this notifyItemChanged position           Map instance Map lt Friend  Integer gt  posMap  is not necessarily required  If map is not used  looping throughout list can find the position of an element

User · Answer

In your RecyclerView adapter  you should have an ArrayList and also one method addItemsToList items  to add list items to the ArrayList  Then you can add list items by call adapter addItemsToList items  dynamically  After all your list items added to the ArrayList then you can call adapter notifyDataSetChanged   to display your list   You can use the notifyDataSetChanged in the adapter for the RecyclerView

User · Answer

I got to solve this issue by catching the position of the item that needed to be modified  and then in the adapter call   public void refreshBlockOverlay int position        notifyItemChanged position         this will call onBindViewHolder ViewHolder holder  int position  for this specific item at this specific position

User · Answer

Below solution worked for me   On a RecyclerView item  user will click a button but another view like TextView will update without directly notifying adapter   I found a good solution for this without using notifyDataSetChanged   method  this method reloads all data of recyclerView so if you have image or video inside item then they will reload and user experience will not good   Here is an example of click on a ImageView like icon and only update a single TextView  Possible to update more view in same way of same item  to show like count update after adding  1      View holder class inside adapter class public class MyViewHolder extends RecyclerView ViewHolder       ImageView imageViewLike       public MyViewHolder View itemView             super itemView            imageViewLike   itemView findViewById R id imageViewLike           imageViewLike setOnClickListener new View OnClickListener                  Override             public void onClick View v                    int pos   getAdapterPosition       Get clicked item position                 TextView tv   v getRootView   findViewById R id textViewLikeCount      Find textView of recyclerView item                 resultList get pos  setLike resultList get pos  getLike     1      Need to change data list to show updated data again after scrolling                 tv setText String valueOf resultList get pos  getLike         Set data to TextView from updated list

User · Answer

Update single item   Update the data item Notify the adapter of the change with notifyItemChanged updateIndex    Example  Change the  Sheep  item so that it says  I like sheep      String newValue    I like sheep    int updateIndex   3  data set updateIndex  newValue   adapter notifyItemChanged updateIndex     My full answer with more examples is here

User · Answer

In your adapter class  in onBindViewHolder method  set ViewHolder to setIsRecyclable false  as in below code    Override public void onBindViewHolder RecyclerViewAdapter ViewHolder p1  int p2           TODO  Implement this method     p1 setIsRecyclable false           Then your other codes

[android] How to update/refresh specific item in RecyclerView

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