Question

我有customrecycleAdapter，当我点击元素时我会改变行的颜色，但如果我滚动视图背景更改位置或出现在其他元素上。我已经阅读了有关Receycle的观点，但是，这个问题的工作原理是什么？

我的适配器是：

public class CustomRecycleAdapter extends RecyclerView.Adapter<CustomRecycleAdapter.ViewHolder> {
    private JSONArray dataSource;
    private AdapterCallback mAdapterCallback;
    public static SparseBooleanArray selectedItems;

    public CustomRecycleAdapter(JSONArray dataArgs, Context context){
        dataSource = dataArgs;
        this.mAdapterCallback = ((AdapterCallback) context);


    }



    public static interface AdapterCallback {
        void onMethodCallback(View caller, JSONObject obj, JSONArray data, int position);
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        // create a new view
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_view_activities, parent, false);

        ViewHolder viewHolder = new ViewHolder(view,  new CustomRecycleAdapter.ViewHolder.IMyViewHolderClicks() {
            public void onClick(View caller, int position) {
                try {

                    JSONObject itemClicked = dataSource.getJSONObject(position);
                    mAdapterCallback.onMethodCallback(caller, itemClicked, dataSource, position);
//                    Log.e("clicked", itemClicked.toString());

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            };
        });

        return viewHolder;

    }

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

            JSONObject object =  dataSource.getJSONObject(position);
            holder.textView.setText(object.getString("description"));





        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
    @Override
    public int getItemCount() {
        return dataSource.length();
    }

    public JSONObject getItem(int position) throws JSONException {
        return dataSource.getJSONObject(position);
    }

    public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

        public IMyViewHolderClicks mListener;
        public TextView textView;
        public TextView hours;

        public ViewHolder(View itemView, IMyViewHolderClicks listener) {
            super(itemView);
            mListener = listener;
            textView = (TextView) itemView.findViewById(R.id.activity);
            hours = (TextView) itemView.findViewById(R.id.hours);
            itemView.setOnClickListener(this);

        }


        @Override
        public void onClick(View v) {
            int position  = getAdapterPosition();
            Log.e("RecycleAdapterPosition", String.valueOf(getAdapterPosition()));
//            mListener.onClick(v, position);
            v.setBackgroundColor(Color.GREEN);
            v.setSelected(true);


        }
        public interface IMyViewHolderClicks {


            public void onClick(View caller, int position);
        }
    }




}

所以我点击了元素，并且正确地设置了背景，但如果我滚动，我会看到另一个元素背景设置，如果我向上滚动我的元素，我选择了，没有背景。

Answer 1

RecyclerView重复使用视图来绘制列表中将要显示的下一个元素，因此视图集包含新数据，但继续使用旧样式，因为您会看到列表中其他元素的新颜色。

你应该创建一个数组存储是否检查了这个元素，并检查是否在调用var numberOfRows = 0 var snusBrandsArray = [String]() override func viewDidLoad() { super.viewDidLoad() parseJSON() } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() } func parseJSON(){ let path: String = NSBundle.mainBundle().pathForResource("snuses", ofType: "json") as String! let jsonData = NSData(contentsOfFile: path) as NSData! let readableJSON = JSON(data: jsonData, options: NSJSONReadingOptions.MutableContainers, error: nil) var brands = readableJSON["Snuses", "Brands"] NSLog("\(brands)") numberOfRows = readableJSON["Snuses"].count for i in 1...numberOfRows{ var brands = "Snuses" brands += "\(i)" var name = readableJSON["Snuses", "Brands"].string as String! snusBrandsArray.append(name) } }时检查了

onBindViewHolder()

使用滚动RecycleAdapter重复元素背景并滚动

1 个答案: