如何在Recyclerview中为未选择的项目设置背景色和文字色？

Question

我正在使用RecyclerView。在我的RecyclerView项目中，我使用的是一个按钮视图。以下是我的RecyclerView项目布局。

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <Button
        android:id="@+id/cost_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
         />


</androidx.constraintlayout.widget.ConstraintLayout>

下面是我的Adapter类。

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private List<Plan> plans;
    private MyInterface myInterface;
    private int index=-1;
    public RecyclerViewAdapter(List<Plan> planList, MyInterface myInterfaceListener) {
        this.plans =planList;
        this.myInterface=myInterfaceListener;
    }

   interface MyInterface{
        public void getId(String id);
   }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view = layoutInflater.inflate(R.layout.recycler_view_item, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myViewHolder=(MyViewHolder) holder;
        myViewHolder.costButton.setText(plans.get(position).getAmount());
        if(index==-1) {
            if(plans.get(0).getAmount().equalsIgnoreCase(plans.get(position).getAmount())) {
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
            }
            else{
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
            }
        }
        myViewHolder.costButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                index=position;
                if(index==position){
                    myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
                    myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
                }
                else{
                    myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
                    myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
                }
            }
        });


    }

    @Override
    public int getItemCount() {
        return plans.size();
    }

    private class MyViewHolder extends RecyclerView.ViewHolder{
        private Button costButton;
        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            costButton=itemView.findViewById(R.id.cost_button);

        }
    }

}

我可以为选中的项目设置背景色和文字色。我的问题是，考虑到有4个按钮，如果我点击按钮1，那么我可以改变颜色。如果我点击按钮1，那么我可以改变颜色。之后，我点击按钮2。在这段时间里，点击项目的颜色会发生变化，而按钮1的颜色也会保持不变。这是我的问题。谁能帮我解决这个问题。

Answer 1

把你的代码片段改成这样。

public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myViewHolder=(MyViewHolder) holder;
        myViewHolder.costButton.setText(plans.get(position).getAmount());
        if(index==-1) {
            if(plans.get(0).getAmount().equalsIgnoreCase(plans.get(position).getAmount())) {
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
            }
            else{
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
            }
        }else{
            if(index==position){
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
            }
            else{
                myViewHolder.costButton.setBackgroundColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.color_white));
                myViewHolder.costButton.setTextColor(myViewHolder.itemView.getContext().getResources().getColor(R.color.blue));
            }
        }
        myViewHolder.costButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                index=position;
               notifyDataSetChanged();
            }
        });


    }

Answer 2

你可以用复选框代替按钮，根据你的需要进行定制。