android - 如何保持 RecyclerView 的按钮被恭敬地点击 - Android

Question

我有一个填充了 CardView 的 RecyclerView。在每个 CardViews 上都有一个按钮，用于对帖子进行投票。

这是按钮未按下时的样子，

这是按下按钮时的样子，

我的代码可以实现这一点，但我遇到了一个问题，因为它是一个 RecyclerView。当我向下滚动帖子时，RecyclerView 会回收之前投票过的帖子。因此，即使用户从未投票过，帖子也会显示它已投票。

如何让每个 CardView 的按钮保持按下状态？

这是我的适配器

public class DiscoverRecyclerAdapter
        extends RecyclerView.Adapter<DiscoverRecyclerAdapter.ViewHolder> {

    private String[] mDataset;

    Typeface customFont;

    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTitle;
        public TextView mVoterCounter;
        public ImageButton mVoterButton;
        public ViewHolder(android.support.v7.widget.CardView v) {
            super(v);
            mTitle = (TextView) v.findViewById(R.id.title);
            mVoterCounter = (TextView) v.findViewById(R.id.voter_counter);

            //Initialize voter button
            mVoterButton = (ImageButton)v.findViewById(R.id.voter);

            mVoterButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mVoterButton.setImageResource(R.drawable.ic_voter_pressed);
                }
            });
        }
    }

    // Provide a suitable constructor (depends on the kind of dataset)
    public DiscoverRecyclerAdapter(String[] myDataset, Typeface passedFont) {
        mDataset = myDataset;
        customFont = passedFont;
    }

    // Create new views (invoked by the layout manager)
    @Override
    public DiscoverRecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_discover, parent, false);
        // set the view's size, margins, paddings and layout parameters
        return new ViewHolder((android.support.v7.widget.CardView)v);
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.mTitle.setText(mDataset[position]);
        holder.mTitle.setTypeface(customFont);
        holder.mVoterCounter.setTypeface(customFont);
    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

Answer 1

除了 mDataset，您还需要一个 bool 数组，比如 mIsSelected现在它的大小将等于数组 mDataSet 的大小，或者如果需要，可以创建类。

然后在 onBindViewHolder 中做

 if(mIsSelected[position]
  mVoterButton.setImageResource(R.drawable.ic_voter_pressed);
else
 mVoterButton.setImageResource(R.drawable.ic_voter_unpressed);

并将按钮 onclick 移动到 onBindViewHolder 中，如下所示

 holder.mVoterButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
              mVoterButton.setImageResource(R.drawable.ic_voter_pressed);
              mIsSelected[position] = true;
            }
        });