RecyclerView+SwipeRefreshLayout简单几步实现下拉刷新、上拉加载

RecyclerView 和SwipeRefreshLayout都是Google官方推出的控件，介绍我这里就不再重复，网上一搜一大把，下面将通过几步简单实现刷新及预加载功能

RecyclerView的初始化等这里也不再重复，只粘贴关键步骤

1、布局代码如下

 < android.support.v4.widget.SwipeRefreshLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            < android.support.v7.widget.RecyclerView
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1" />
        < /android.support.v4.widget.SwipeRefreshLayout>

2、下拉刷新部分

mSwipeRefreshLayout.setColorSchemeResources(R.color.blue_FF44BBF0, R.color.green_FF46CD63, R.color.red_FFFC789E, R.color.yellow_FFFFB700);
      mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
          @Override
          public void onRefresh() {
              LogUtils.d(TAG, "onRefresh start");
              startRefreshRoomDataTask();

          }
      });

3、上拉加载部分

 mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);

                LogUtils.e(TAG, "onScrollStateChanged: newState :" +newState);

            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                LogUtils.e(TAG, "onScrolled: dx" + dx + "---dy" + dy);

                int lastVisibleItem = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition();
                int totalItemCount = mLayoutManager.getItemCount();//总条目
                //lastVisibleItem >= totalItemCount - 5 表示剩下5个item实现预加载
                // dy>0 表示向下滑动,滑动距离
                if (totalItemCount >= 10 && lastVisibleItem >= totalItemCount - 5 && dy > 0) {

                    if (mIsLoadingMore) {
                        ToastUtils.showWithShort(getApplicationContext(), "已经预加载了!");
                    } else {
                        StartLoadMoreTask();//加载更多
                    }
                }
            }
        });