最近项目中遇到一个问题,app首页的Activity中由若干个Fragment页面组成,其中一个fragment页面是由一个GridView和ListView组成的列表,若是列表中数据量过大的时候,在请求数据的时候点击页面上的其余按钮会无响应,直到该fragment上的数据刷新完页面才会有反应,通过测试是因为fragment请求完数据刷新UI界面与Activity中的底部按钮都是共用的Activity UI主线程,因此只能同时响应一个,解决方案就是对列表数据进行分页处理,并用RecyclerView实现列表。app
分页处理就是请求完接口获得数据,做为总数据,刷新、加载时经过page再获取每页须要获取的数据,刷新页面,进行一些相关的操做便可,在此就不作赘述了。ide
使用RecyclerView实现的好处是能够利用其局部刷新的特色,减小由于notifyDataSetChanged()带来的没必要要的开销,此处用一个RecyclerView实现了GridView和ListView,用viewType属性实现两种布局的效果。布局
设置GridLayoutManager的列数为两列,而后经过itemViewType值判断item占用的列数。测试
final GridLayoutManager manager = new GridLayoutManager(getActivity(), 2); //设置占用的列数 manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() { @Override public int getSpanSize(int position) { int type = rvXiangmu.getAdapter().getItemViewType(position); Log.i("pp", position + ":" + type); //如果TYPE_ONE,占用两列,不然占用一列,分母为grid设置的列数 if (type == TaskTeamEntity2.TYPE_ONE) { return manager.getSpanCount(); } else { return 1; } } }); rvXiangmu.setLayoutManager(manager);
给item绘制间距spa
rvXiangmu.addItemDecoration(new RecyclerView.ItemDecoration() { @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { super.getItemOffsets(outRect, view, parent, state); //给布局里的子view添加边距 GridLayoutManager.LayoutParams layoutParams = (GridLayoutManager.LayoutParams) view.getLayoutParams(); int position = parent.getChildPosition(view); //spanSize表示item占用几列 int spanSize = layoutParams.getSpanSize(); //若是是GridView的话绘制 //表示item占用的列数不是manager设置的总列数,表示一行多列的状况 if (spanSize!=manager.getSpanCount()) { int spanIndex = layoutParams.getSpanIndex(); outRect.bottom = ScreenUtil.dip2px(getActivity(), 4); if (spanIndex == 0) { outRect.left = ScreenUtil.dip2px(getActivity(), 8); outRect.right = ScreenUtil.dip2px(getActivity(), 2); } else { outRect.right = ScreenUtil.dip2px(getActivity(), 8); outRect.left = ScreenUtil.dip2px(getActivity(), 2); } if (position == 0 || position == 1) { outRect.top = ScreenUtil.dip2px(getActivity(), 4); } } } });
adapter中部分代码.net
//建立新View,被LayoutManager所调用 @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) { //根据不一样的viewType,建立并返回相应的ViewHolder switch (viewType) { case TaskTeamEntity2.TYPE_TWO: return new TypeTwoHolder(mLayoutInflater.inflate(R.layout.item_item1, viewGroup, false)); case TaskTeamEntity2.TYPE_ONE: return new TypeOneHolder(mLayoutInflater.inflate(R.layout.item_item2, viewGroup, false)); } return null; }
public class TypeOneHolder extends TypeAbstarctViewHolder { private TextView itemNameTv; private TextView itemTimeTv; public TypeOneHolder(View view) { super(view); itemNameTv = (TextView) view.findViewById(R.id.tv_item_name); itemTimeTv = (TextView) view.findViewById(R.id.tv_item_time); } @Override public void bindHolder(TaskTeamEntity2 item, int position) { itemNameTv.setText(item.t_teamName); itemTimeTv.setText(item.t_enddate); } }
//自定义的ViewHolder,持有每一个Item的的全部界面元素 public class TypeTwoHolder extends TypeAbstarctViewHolder { private TextView itemNameTv; private TextView itemTimeTv; public TypeTwoHolder(View view) { super(view); itemNameTv = (TextView) view.findViewById(R.id.tv_item_name); itemTimeTv = (TextView) view.findViewById(R.id.tv_item_time); } @Override public void bindHolder(TaskTeamEntity2 item, int position) { itemNameTv.setText(item.t_teamName); itemTimeTv.setText(item.t_enddate); } }
public abstract class TypeAbstarctViewHolder extends RecyclerView.ViewHolder { public TypeAbstarctViewHolder(View itemView) { super(itemView); } public abstract void bindHolder(TaskTeamEntity2 item, int position); }