最近項目中遇到一個問題,app首頁的Activity中由若干個Fragment頁面組成,其中一個fragment頁面是由一個GridView和ListView組成的列表,如果列表中數據量過大的時候,在請求數據的時候點擊頁面上的其他按鈕會無響應,直到該fragment上的數據刷新完頁面才會有反應,經過測試是由于fragment請求完數據刷新UI界面與Activity中的底部按鈕都是共用的Activity UI主線程,所以只能同時響應一個,解決方案就是對列表數據進行分頁處理,并用RecyclerView實現列表。
分頁處理就是請求完接口得到數據,作為總數據,刷新、加載時通過page再獲取每頁需要獲取的數據,刷新頁面,進行一些相關的操作即可,在此就不做贅述了。
使用RecyclerView實現的好處是可以利用其局部刷新的特點,減少因為notifyDataSetChanged()帶來的不必要的開銷,此處用一個RecyclerView實現了GridView和ListView,用viewType屬性實現兩種布局的效果。
設置GridLayoutManager的列數為兩列,然后通過itemViewType值判斷item占用的列數。
final GridLayoutManager manager = new GridLayoutManager(getActivity(), 2);//設置占用的列數manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {@Overridepublic int getSpanSize(int position) {int type = rvXiangmu.getAdapter().getItemViewType(position);Log.i("pp", position + ":" + type);//若是TYPE_ONE,占用兩列,否則占用一列,分母為grid設置的列數if (type == TaskTeamEntity2.TYPE_ONE) {return manager.getSpanCount();} else {return 1;}}});rvXiangmu.setLayoutManager(manager);
給item繪制間距
rvXiangmu.addItemDecoration(new RecyclerView.ItemDecoration() {@Overridepublic void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {super.getItemOffsets(outRect, view, parent, state);//給布局里的子view添加邊距GridLayoutManager.LayoutParams layoutParams = (GridLayoutManager.LayoutParams) view.getLayoutParams();int position = parent.getChildPosition(view);//spanSize表示item占用幾列int spanSize = layoutParams.getSpanSize();//如果是GridView的話繪制//表示item占用的列數不是manager設置的總列數,表示一行多列的情況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中部分代碼
//創建新View,被LayoutManager所調用@Overridepublic RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {//根據不同的viewType,創建并返回相應的ViewHolderswitch (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);}@Overridepublic void bindHolder(TaskTeamEntity2 item, int position) {itemNameTv.setText(item.t_teamName);itemTimeTv.setText(item.t_enddate);}}
//自定義的ViewHolder,持有每個Item的的所有界面元素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);}@Overridepublic 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);}
優雅的使用RecyclerView(在一個recyclerView里顯示有不同子布局的界面,就是混合不同布局)
一個簡單的RecyclerView多布局實現
RecycleView 實現復雜首頁布局三種方式