java - 如何更改按钮图像，如切换按钮 RecyclerView 按钮以编程方式单击

Question

我有一个 RecyclerView，其中填充了 ListView。在每个 ListView 上都有一个 Button，用于添加列表。

这是按钮未按下时的样子

这是按下按钮时的样子，

如何让每个 ListView 的按钮都被按下？

这是我的适配器

  public class BuildCustomAdapter extends RecyclerView.Adapter<BuildCustomAdapter.MyViewHolder> implements Filterable {
    private int previousTotal = 0;
    private boolean loading = true;
    private List<Build> buildList;
    private List<Build> buildListCopy;
    private ItemFilter mFilter = new ItemFilter();


    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.build_list_row, parent, false);

        return new MyViewHolder(itemView);
    }

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

       Build build = buildList.get(position);
        holder.imageView.setImageResource(build.getImages());
        holder.name.setText(build.getName());

    }

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

    @Override
    public Filter getFilter() {
        if (mFilter == null) {
            mFilter = new ItemFilter();
        }
        return mFilter;
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {
        public ImageView imageView;
        public TextView name;
        public Button button;

        public MyViewHolder(View itemView) {
            super(itemView);
            imageView = (ImageView) itemView.findViewById(R.id.ivPerson);
            name = (TextView) itemView.findViewById(R.id.tvPersonName);
            button = (Button) itemView.findViewById(R.id.addbn);

        }
    }

    private class ItemFilter extends Filter {


            protected FilterResults performFiltering(CharSequence constraint) {
                FilterResults results = new FilterResults();

                if (constraint != null && constraint.length() > 0) {
                    List<Build> filterList = new ArrayList<Build>();

                    for (int i = 0; i < buildList.size(); i++) {
                        if ((buildList.get(i).getName().toUpperCase())
                                .contains(constraint.toString().toUpperCase())) {
                            Build builddata = new Build(buildList.get(i).getImages(), buildList.get(i).getName());

                            filterList.add(builddata);
                        }
                    }
                    results.count = filterList.size();
                    results.values = filterList;

                } else {
                    results.count = buildList.size();
                    results.values = buildList;
                }
                return results;
            }

        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {

            buildList = (ArrayList<Build>) results.values;
          notifyDataSetChanged();
        }

    }


    public BuildCustomAdapter(List<Build> buildList) {
        this.buildList = buildList;
    }


}

Build.class

public class Build {
    private String name;
    private int images;

    public Build(int images, String name) {
        this.images = images;
        this.name = name;
    }

    public int getImages() {
        return images;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

Answer 1

如果你在 pojo 类中使用 selected 作为 boolean 变量会更好，它会帮助适配器根据状态设置图像。实际上，每当你向上和向下滚动时，不可见的项目就会从内存中移除，并且我们已经根据按钮事件更新了我们的列表，所以第二次它会获取所需的状态并再次显示之前的状态图像。

BuildCustomAdapter 每当您创建适配器时始终传递上下文，上下文会帮助您

 Context context;
    public BuildCustomAdapter(List<Build> buildList,Context context) {
            this.buildList = buildList;
            this.context = context;
        }

Build.java

public class Build {
        private String name;
        private int images;
        private boolean selected;

        public Build(boolean selected, String name,int images) {
            this.images = images;
           this.selected=selected; 
           this.name = name;
        }

        public int getImages() {
            return images;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public void setSeleted(boolean selected){
            this.selected=selected;
        }

        public boolean isSelected(){
            return selected;
        } 
    }

你的适配器

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

            Build build = buildList.get(position);

            holder.imageView.setImageResources(build.getImages());

            holder.name.setText(build.getName());
            setImageIntoButton(holder.button,build.isSelected());

            holder.button.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        build.setSelected(!build.isSelected());
                        setImageIntoButton(holder.button,build.isSelected());
                    }
                });
        }

      private void setImageIntoButton(Button buttonView,boolean isSelected){
         if(isSelected)
           buttonView.setBackgroundResource(R.drawable.clicked_image); 
            else 
          buttonView.setBackgroundResource(R.drawable.cross_image); 
 }

项目过滤器更改此声明

Build builddata = new Build(buildList.get(i).isSelected(), buildList.get(i).getName(),buildList.get(i).getImages());