How To Update The Value Of The Textview Inside The Fragment On The Click Of The Button Present In The Adapter Class In Android?

I have two buttons: + and -. I want that when I click on the button +, the value of the textview present in the fragment class (outside the listview) is changed. How can I do this

Solution 1:

In your Adapter class create one interface

Adapter.class

publicclassCartBaseAdapterextendsBaseAdapter {

    private Context mContext;
    private ArrayList<PojoCart> mList;
    private ViewHolder viewHolder;
    private HashMap<String, Integer> mHashMap = newHashMap<String, Integer>();
    private Integer total;
    private DataBaseHandler dbh;
    privateintId=1;
    private String value1, value2;
    privateint z;
    privateFragmentTransactionListenerfragmentTransactionListener= (FragmentTransactionListener) newCart();
    private SendDataToFragment sendDataToFragment;

    publicCartBaseAdapter(FragmentCart fragmentCart, Context mContext, ArrayList<PojoCart> mList) {
        this.mContext = mContext;
        this.mList = mList;
        dbh = newDataBaseHandler(mContext);
        sendDataToFragment = (SendDataToFragment) fragmentCart;

    }

    //Interface to send data from adapter to fragmentpublicinterfaceSendDataToFragment {
        voidsendData(String Data);
    }


    @OverridepublicintgetCount() {
        return mList.size();
    }

    @Overridepublic Object getItem(int position) {
        return mList.get(position);
    }

    @OverridepubliclonggetItemId(int position) {
        return position;
    }


    @Overridepublic View getView(finalint position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            LayoutInflaterinflater= (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.cart_item, parent, false);

            viewHolder = newViewHolder();
            viewHolder.mImgItem = (ImageView) convertView.findViewById(R.id.cart_image);
            viewHolder.mTvItemName = (TextView) convertView.findViewById(R.id.tv_item_name);
            viewHolder.mTvItemPrice = (TextView) convertView.findViewById(R.id.tv_item_price);
            viewHolder.mTvNumber = (TextView) convertView.findViewById(R.id.tv_number);
            viewHolder.mBtnAdd = (Button) convertView.findViewById(R.id.btn_add);
            viewHolder.mBtnMinus = (Button) convertView.findViewById(R.id.btn_sub);
            viewHolder.mImgDelete = (ImageView) convertView.findViewById(R.id.img_del);

        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }


        convertView.setTag(viewHolder);


        finalPojoCartpojoCart= (PojoCart) getItem(position);
        viewHolder.mTvItemName.setText(pojoCart.getmItemName());
        viewHolder.mTvItemPrice.setText(pojoCart.getmItemPrice());


        viewHolder.mImgItem.setImageBitmap(Utility.StringToBitMap(pojoCart.getmItemImage()));
        viewHolder.mBtnAdd.setTag(pojoCart);
        viewHolder.mBtnMinus.setTag(pojoCart);
        viewHolder.mTvItemPrice.setTag(pojoCart);
        viewHolder.mTvNumber.setTag(pojoCart);
        viewHolder.mImgDelete.setTag(position);

        if (pojoCart.getmQuantity() > 0) {

            viewHolder.mTvNumber.setText("" + pojoCart.getmQuantity());

        } else {

            viewHolder.mTvNumber.setText("" + 0);
        }


        viewHolder.mBtnAdd.setOnClickListener(newView.OnClickListener() {
            @OverridepublicvoidonClick(View v) {
                //Send data via interface to your fragment
                sendDataToFragment.sendData("Your Data");

                //Your existing code 
            }
        });

        viewHolder.mBtnMinus.setOnClickListener(newView.OnClickListener() {
            @OverridepublicvoidonClick(View v) {
                //Send data via interface to your fragment
                sendDataToFragment.sendData("Your Data");

                //Your existing code 
            }
        });

        return convertView;
    }


    privateclassViewHolder {

        TextView mTvItemName, mTvItemPrice, mTvNumber;
        ImageView mImgItem, mImgDelete;
        Button mBtnAdd, mBtnMinus;


    }


}

Inside your fragment implement that interface so as soon as your button is clicked in your adapter you will get the data inside your fragment.

Fragment.class

publicclassFragmentCartextendsFragmentimplementsView.OnClickListener, CartBaseAdapter.SendDataToFragment{

    @Nullable@OverridepublicViewonCreateView(LayoutInflater inflater, ViewGroup container,   Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.your_layout, null);
        return rootView;
    }

    @OverridepublicvoidonViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        CartBaseAdapter adapter = newCartBaseAdapter(FragmentCart.this, getActivity(), yourList);

    }

    @OverridepublicvoidonClick(View v) {

    }

    @OverridepublicvoidsendData(String Data) {
        //set this data to your textView
    }
}

Solution 2:

Create a interface :

publicinterfaceMyListener {
    // you can define any parameter as per your requirementpublicvoidcallback(View view, intvalue);
}

In your listview adapter use interface like below on click of button + or - like :

MyListener ml;
ml = (MyListener) context;
ml.callback(this, "success");

In activity implements MyListener than callback method override there and than you get performed action from fragment to activity.