How to get the position of cardView item in recyclerView?

Question

I created one adapter class for recycler for populating cardview layout in recyclerview. It is working fine, but when i click cardView item in recyclerview i need to get pos

Answer 1

Short Answer

1. Getting the position of CardView item

   when i click cardView item in recyclerview i need to get position of that cardview item

   use setTag() in the onBindViewHolder method of your adapter and getTag() in your OnClickListener implementation.

   you can also use getAdapterPosition() - see https://stackoverflow.com/a/27886776/4658957

   EDIT: as mentioned in the comments if you need to implement swipes, use the getAdapterPosition() method instead - this makes sure that the positions are not off.

2. Launching an activity

   based on that i need to write a Intent activity

   create and start a new Intent in your OnClickListener implementation

   Intent newIntent = new Intent(this, YourNewActivity.class);    
   startActivity(newIntent);
   

Long Answer

How to get the position of a CardView item in the RecyclerView list?

when i click cardView item in recyclerview i need to get position of that cardview item

I used the setTag() and getTag() methods of View. You can also use getAdapterPosition - see https://stackoverflow.com/a/27886776/4658957

The View can be a TextView, ImageView, CardView, even a View (which could contain text views, image views and so forth) - basically ok if it inherits from the View Object.

• first, look at the onCreateViewHolder method below. layoutInflater inflates the views in my XML layout file item_view.xml. Any views in that layout file will be accessible in the constructor.

  @Override
  public myViewHolder onCreateViewHolder(ViewGroup parentViewGroup, int i) {
      ...
  
      View itemView = layoutInflater.inflate(R.layout.item_view, parentViewGroup, false);
      return new myViewHolder(itemView);
  }
  

• define a constant for your View object such as mView and set it to the View you wish to set the onClickListener to / get the position from.

  private class myViewHolder extends RecyclerView.ViewHolder {
      public View mView;
  
      public myViewHolder(View view) {
          super(view);
          mView = view;
      }
  }
  

  In the previous case, I set mView to the parent View.

  If you want to access a specific View from the item_view.xml layout file inflated in onCreateViewHolder -- define another constant, set it using view.findViewbyId() and do not forget to cast the View (see below).

  private class myViewHolder extends RecyclerView.ViewHolder {
      public CardView mCardView;
  
      public myViewHolder(View view) {
          super(view);
          mCardView = (CardView) view.findViewById(R.id.card_view);
      }
  }
  

• use setTag() in the onBindViewHolder method of your adapter class. Each CardView now has its position in the RecyclerView list as a tag.

  @Override
  public void onBindViewHolder(myViewHolder viewHolder, int position) {
      viewHolder.mCardView.setTag(position);
  }
  

• use getTag() to access the position of each CardView in your RecyclerView list: we have 2 ways for this (in Activity or in XML).

  set onClickListener in your ViewHolder constructor (do not forget to implement View.OnClickListener) and edit the onClick method

  private class myViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
             public View mCardView;
  
             public myViewHolder(View view) {
                 super(view);
                 mCardView = (CardView) view.findViewById(R.id.card_view);
  
                 mCardView.setOnClickListener(this);
             }
         }
  
  @Override
  public void onClick(View view) {
      int position = (int) view.getTag();           
      Toast.makeText(view.getContext(),Integer.toString(position),Toast.LENGTH_SHORT).show();
  }
  

  OR set the onClick attribute in your XML layout for CardView android:onClick="positionAction"

  and create a method in the activity that contains the recycler view.

  public void positionAction(View view) {
      int position = (int) view.getTag();
      Toast.makeText(view.getContext(),Integer.toString(position),Toast.LENGTH_SHORT).show();
  }
  

For both options above, you can use String position = "Position " + view.getTag.toString(); instead of int position = (int) view.getTag; if you want to obtain the position as a String.

Note 1: You can only use getTag() on View objects whose setTag() method has been called (or else you will get a NullPointerException).

Note 2: I did not use a key for the setTag() and getTag() methods, which you could have done if you are setting several tags for each View.

How to start an activity based on the CardView clicked?

based on that i need to write a Intent activity

To start a new activity based on the CardView item the user clicks on, add the two lines below in the onClick method or in the positionAction method (based on the one you chose to use).

Intent newIntent = new Intent(this, YourNewActivity.class);    
startActivity(newIntent);

If you want to pass an object from one activity to the other, use

Intent newIntent = new Intent(this, YourNewActivity.class);
newIntent.putExtra("Item Object", itemList.get(position));
startActivity(newIntent);

and in the new activity (YourNewActivity class) :

itemReceived = new Item();
itemReceived = (Item) getIntent().getSerializableExtra("Item Object");

where itemList is an ArrayList of Item() objects.

References: StackOverflow | Tuts+