Skip to main content

How to access the each view of item by position in Recycler View in android ?

How to access the each view of item by position in Recycler View in android ?


 There are some methods to access the view of each item view to change or update the view during the run time. To access the view of the item view ,

consider the Recycler view as below,


 RecyclerView mainRecyclerView = (RecyclerView)view.findViewById(R.id.main_recycler_view);

RecyclerAdapter adapter = new RecyclerAdapter(mContext);

mainRecyclerView.setAdapter(adapter);

main.setLayoutManager(new LinearLayoutManager(mContext));

 To access the itemView of each position the following functions can be used,

 1. View itemView = mainRecyclerView.getChildAt(positionOfItem);

 2. View itemView = mainRecyclerView.findViewHolderForAdapterPosition(Position).itemView;

 3. View itemView = mainRecyclerView.findViewHolderForPosition(Position).itemView;

 4. Long itemId = mainRecyclerView.getAdapter().getItemId(position);  

    View itemView = mainRecyclerView.findViewHolderForItemId(itemId);

 5. View itemView = mainRecyclerView.getLayoutManager().findViewByPosition(Position);

 6. View itemView = mainRecyclerView.getLayoutManager().getChildAt(position);


 After getting the rootView of each item using above methods you can access each element inside the view using the ,
itemView.findViewById();

 and you can do as normal to update the view at runtime.

 But one of the problem is that if you guys all the above methods normally from the oncreate or createView or any method of fragment or activity it will throw you the null pointer exception as.

 android.View.View.findViewById() java.lang.null null pointer exception.

 Always these methods should be called from any of the event listeners like onTouchListener or onClickListener or onScrollListener etc as per the requirement.

 But if the requirement is like you need to call simply without any event listener then, use the methods as shown below,

 mainRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener()
{
       View itemView = mainRecyclerView.getChildAt(positionOfItem);
        mainRecyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}

Cool !! The issue is solved for those are thirsty for this...!! Keep reading the blog for lots of solutions..!!
Incoming Keywords:
findviewholderforitemid null, findviewholderforitemid, findviewholderforadapterposition null, findviewholderforlayoutposition, findviewholderforposition, 
recyclerview getchildat null, recyclerview getchildat returns null, findviewholderforadapterposition returns null, android recyclerview get viewholder at position

Comments

Post a Comment

Popular posts from this blog

How Machine Learning Works ? - Data Rules the Kingdom

W elcome Back Readers !, For those who have not read the previous post on How Machine Learning works ? Please do read previous one before continuing this so that it would be more easy to understand. You can find the previous post here How Machine Learning Works ? - Mathematics Every Where . For other who are ready to join with me in this journey to understand the Machine Learning, Thank you for being with this post. Till now we are discussing on the the title "How Machine Learning works? " and to understand that we have seen in the first post that there exist the patterns or trends in the data and we try to find that in terms of a mathematical equation called a model and try to fit to the new data that we have not came across for predicting the values. Wow may be we got the entire process complete with this. But there are few thinks that needs to be cared while training the model or creating the model or while processing the data for the model creation. ...
3 comments
Read more

Machine Learning - Types of Learning - Explained

W elcome back readers !! So far we are trying to understand the Machine learning in a simple way, keeping the beginners context in mind ! This is one more post, I thought I would write on explaining the various learning types in the Machine Learning. Obviously the word says "Machine Learning" - means machine learn something. How do machine can learn something is what we understood in our various posts before ( here ). We will see about how many types of learning are possible by the machines. Here when I say types of learning, I say about the various classification of learning procedures (Algorithm - Step by step procedure to solve a problem). Types of Learning: Following types of learning procedures can be identified, Regression Classification Clustering Rule association  Ensemble  Reinforcement Deep Learning I can understand that this sounds Greek and Latin now, trust me I will make you understand all this in easy way. We can't cover all the types...
2 comments
Read more