如何在Recycler视图中更改所选项目的文本颜色

Question

I have a list of items using recycler view. I need to change the text color (textview color) of item when it is selected to indicate that the particular item is selected. Below is my adapter code. Kindly suggest me how to achieve this.

@Override
public GridView_Holder onCreateViewHolder(ViewGroup viewGroup, int viewType) {

    View itemView = LayoutInflater.from(viewGroup.getContext())
            .inflate(R.layout.grid_customview, viewGroup, false);

    gridHolder = new GridView_Holder(itemView);
    ColorDrawable colorDrawableSelected = new ColorDrawable(context.getResources().getColor(R.color.borderColor));
    // create StateListDrawable object and define its states
    StateListDrawable stateListDrawable = new StateListDrawable();
    stateListDrawable.addState(new int[]{android.R.attr.state_selected}, colorDrawableSelected);
    stateListDrawable.addState(StateSet.WILD_CARD, null);
    // set the StateListDrawable as background of the item view
    if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.JELLY_BEAN) {
        itemView.setBackgroundDrawable(stateListDrawable);
    }
    else {
        itemView.setBackground(stateListDrawable);
    }

    return  new GridView_Holder(itemView);
}


@Override
public void onBindViewHolder(GridView_Holder holder, int position) {

    model = arrayList.get(position);
    gridHolder = (GridView_Holder) holder;// Holder
    gridHolder.tvTitle.setText(model.getVideoName());    //set title                        

    Glide.with(context).load(model.getVideoImageThumbnail())
            .diskCacheStrategy(DiskCacheStrategy.ALL)
            .into(gridHolder.imageView);
}


@Override
public void onAttachedToRecyclerView(final RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
    recyclerView.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {

            GridLayoutManager lm = ((GridLayoutManager) recyclerView.getLayoutManager());
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN)
                {
                    if(mCurrentSelectedPosition + 6 < getItemCount())
                    {
                        gridHolder = (GridView_Holder) mRecyclerView.findViewHolderForPosition(mCurrentSelectedPosition);
                        gridHolder.itemView.setSelected(false);
                        notifyItemChanged(mCurrentSelectedPosition);
                        int lastItem = lm.findLastCompletelyVisibleItemPosition();
                        if((mCurrentSelectedPosition+6) > lastItem)
                        {
                        recyclerView.smoothScrollToPosition(mCurrentSelectedPosition+6);
                        }
                        else
                        {
                            gridHolder = (GridView_Holder) mRecyclerView.findViewHolderForPosition(mCurrentSelectedPosition+6);
                            gridHolder.itemView.setSelected(true);
                        }

                        mCurrentSelectedPosition += 6 ;
                    }
                    return true;
                }
                else if (keyCode == KeyEvent.KEYCODE_DPAD_UP) 
                {
                }

                else if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
                    if(mCurrentSelectedPosition + 1 < getItemCount())
                    {
                        gridHolder = (GridView_Holder) mRecyclerView.findViewHolderForPosition(mCurrentSelectedPosition);
                        gridHolder.itemView.setSelected(false);
                        notifyItemChanged(mCurrentSelectedPosition);
                        int lastItem = lm.findLastCompletelyVisibleItemPosition();
                        if((mCurrentSelectedPosition+1) > lastItem)
                        {
                                                        recyclerView.smoothScrollToPosition(mCurrentSelectedPosition+1);
                        }
                        else
                        {
                            gridHolder = (GridView_Holder) mRecyclerView.findViewHolderForPosition(mCurrentSelectedPosition+1);
                            gridHolder.itemView.setSelected(true);
                        }
                        mCurrentSelectedPosition += 1 ;
                    }
                    return true;
                }
                return false;
        }
    });
}

Answer 1

In your GridView_Holder class:

public final TextView textView,

    public GridView_Holder(View itemView, int type) {
                super(itemView);
                textView = (TextView) itemView.findViewById(R.id.tv);
            }

         @Override
            public void onItemSelected() {
               textView.setTextColor(ContextCompat.getColor(context, R.color.accent));
            }

        @Override
            public void onItemClear() {
              textView.setTextColor(ContextCompat.getColor(context, R.color.primary));
            }