RecyclerView实现多行多列item单选点击变色

今天工作的时候遇到一个需求，需要实现多行多列单选，并且点击变色的功能，一开始我是想用RadioButton来实现的，但是RadioGroup只能是单行纵向或者横向，如果要实现多行多列的话，必须自定义一个RadioGroup，最终我还是选择用RecyclerView来实现。

思路

1、首先自定义一个适配器，将列表的子项的布局设置好，并设置好点击事件，同时定义一个Map用来存储每个子项的ViewHolder，在Adapter中定义一个函数，用来实现子项点击后刷新自身背景的功能；

2、RecyclerView设置布局管理器为网格布局管理器GridLayoutManager，设置adapter的点击事件，设置间距

实现

自定义Adapter

public class FilterBureauAdapter extends RecyclerView.Adapter<FilterBureauAdapter.FilterBureauHolder> {

    private Context mContext;
    private String[] mList;
    private Map<Integer,FilterBureauHolder> mHolderMap;

    public FilterBureauAdapter(Context context, @NonNull String[] list) {
        mContext = context;
        mList = list;
        mHolderMap = new HashMap<>();
    }
    @Override
    public FilterBureauHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.list_item_filter_bureau,parent,false);
        FilterBureauHolder holder = new FilterBureauHolder(view);
        return holder;
    }

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

    @Override
    public void onBindViewHolder(final FilterBureauHolder holder, final int position) {
        holder.btnBureau.setText(mList[position]);
        holder.btnBureau.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onItemClickListener.onItemClick(v,position);
            }
        });
        // 保存子项的ViewHolder
        mHolderMap.put(position,holder);
    }

    /**
     * 刷新区局按钮点击状态
     */
    public void refreshBureau(int position){
        for (Map.Entry<Integer,FilterBureauHolder> entry: mHolderMap.entrySet()) {
            FilterBureauHolder holder = entry.getValue();
            // 点击项背景以及字体变色，其它项背景及字体设置为默认颜色
            if (entry.getKey() == position){
                holder.btnBureau.setBackgroundResource(R.mipmap.icon_filterbox_on);
                holder.btnBureau.setTextColor(mContext.getResources().getColor(R.color.main_blue));
            } else {
                holder.btnBureau.setBackgroundResource(R.mipmap.icon_filterbox_off);
                holder.btnBureau.setTextColor(mContext.getResources().getColor(R.color.main_gray));
            }
        }
    }

    class FilterBureauHolder extends RecyclerView.ViewHolder{
        Button btnBureau;
        public FilterBureauHolder(View itemView) {
            super(itemView);
            btnBureau = (Button) itemView.findViewById(R.id.btn_bureau);
        }
    }

    private OnItemClickListener onItemClickListener;

    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.onItemClickListener = onItemClickListener;
    }
}

其中OnItemClickListener 为自定义的接口

public interface OnItemClickListener {
    void onItemClick(View view, int position);
    void onItemLongClick(View view , int position);
}

布局文件比较简单，就放了一个按钮

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <Button
        android:id="@+id/btn_bureau"
        android:layout_width="60dp"
        android:layout_height="32dp"
        android:background="@mipmap/icon_filterbox_off"
        android:textColor="@color/main_gray"/>
</LinearLayout>

然后就在Fragment中实例一个RecyclerView，设置好布局管理器、间距、适配器以及每一项的点击事件，这里我设置为网格布局，3列，然后设置子项间的间距为16dp

 public void initFilterBureau() {
        rvBbureau.setLayoutManager(new GridLayoutManager(getActivity(),3,GridLayoutManager.VERTICAL,false));
        rvBbureau.addItemDecoration(new GridSpacingItemDecoration(3, Util.dip2px(getActivity(),16),true));
        final FilterBureauAdapter adapter = new FilterBureauAdapter(getActivity(), Constant.BUREAUS);
        adapter.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                // 点击项后刷新每一项的背景及字体颜色
                adapter.refreshBureau(position);
            }

            @Override
            public void onItemLongClick(View view, int position) {

            }
        });
        rvBbureau.setAdapter(adapter);

    }

这里的间距设置是需要自定义的

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
    private int spanCount;
    private int spacing;
    private boolean includeEdge;

    public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
        this.spanCount = spanCount;
        this.spacing = spacing;
        this.includeEdge = includeEdge;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view); // item position
        int column = position % spanCount; // item column

        if (includeEdge) {
            outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
            outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)

            if (position < spanCount) { // top edge
                outRect.top = spacing;
            }
            outRect.bottom = spacing; // item bottom
        } else {
            outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
            outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f /    spanCount) * spacing)
            if (position >= spanCount) {
                outRect.top = spacing; // item top
            }
        }
    }
}

以上就是所有的实现过程了