分页使用改造在Android中滚动时从API获取下10个项目

Question

使用改进的分页在Android中滚动时从API获取下10个项目

Answer 1

代替，

如果您使用简单的listview和BaseAdapter进行分页， 那么你可以按照下面的代码。

使用2个arrayList作为paginataion。 一个是加载所有listview项（allDataList），一个是在adapter（paginationList）中设置10个项目。

首先使用改造加载allDataList中的所有数据。

{{1}}

希望这有帮助。

Answer 2

在您的recycleview ScrollListener

中

private static final int PAGE_START = 0;
private boolean isLoading = false;  
private boolean isLastPage = false;   
private int TOTAL_PAGES = 3; //your total page
private int currentPage = PAGE_START;





rv.addOnScrollListener(new PaginationScrollListener(linearLayoutManager) {
        @Override
        protected void loadMoreItems() {
            isLoading = true;
            currentPage += 1;
            loadApi(currentPage); //pass page number as parameter in your api calls
        }

        @Override
        public int getTotalPageCount() {
            return TOTAL_PAGES;
        }

        @Override
        public boolean isLastPage() {
            return isLastPage;
        }

        @Override
        public boolean isLoading() {
            return isLoading;
        }
    });


}

更多详情请参阅Pagination Android RecyclerView

Answer 3

在EndlessRecyclerViewScrollListener类下面使用。

 public abstract class EndlessRecyclerViewScrollListener extends RecyclerView.OnScrollListener {
        // The minimum amount of items to have below your current scroll position
        // before loading more.
        private int visibleThreshold = 5;
        // The current offset index of data you have loaded
        private int currentPage = 0;
        // The total number of items in the dataset after the last load
        private int previousTotalItemCount = 0;
        // True if we are still waiting for the last set of data to load.
        private boolean loading = true;
        // Sets the starting page index
        private int startingPageIndex = 0;

        RecyclerView.LayoutManager mLayoutManager;

        public EndlessRecyclerViewScrollListener(LinearLayoutManager layoutManager) {
            this.mLayoutManager = layoutManager;
        }

        public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) {
            this.mLayoutManager = layoutManager;
            visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
        }

        public EndlessRecyclerViewScrollListener(StaggeredGridLayoutManager layoutManager) {
            this.mLayoutManager = layoutManager;
            visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
        }

        public int getLastVisibleItem(int[] lastVisibleItemPositions) {
            int maxSize = 0;
            for (int i = 0; i < lastVisibleItemPositions.length; i++) {
                if (i == 0) {
                    maxSize = lastVisibleItemPositions[i];
                } else if (lastVisibleItemPositions[i] > maxSize) {
                    maxSize = lastVisibleItemPositions[i];
                }
            }
            return maxSize;
        }

        // This happens many times a second during a scroll, so be wary of the code you place here.
        // We are given a few useful parameters to help us work out if we need to load some more data,
        // but first we check if we are waiting for the previous load to finish.
        @Override
        public void onScrolled(RecyclerView view, int dx, int dy) {
            int lastVisibleItemPosition = 0;
            int totalItemCount = mLayoutManager.getItemCount();

            if (mLayoutManager instanceof StaggeredGridLayoutManager) {
                int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findLastVisibleItemPositions(null);
                // get maximum element within the list
                lastVisibleItemPosition = getLastVisibleItem(lastVisibleItemPositions);
            } else if (mLayoutManager instanceof GridLayoutManager) {
                lastVisibleItemPosition = ((GridLayoutManager) mLayoutManager).findLastVisibleItemPosition();
            } else if (mLayoutManager instanceof LinearLayoutManager) {
                lastVisibleItemPosition = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition();
                if (((LinearLayoutManager) mLayoutManager).findFirstCompletelyVisibleItemPosition() == 0) {
                    doPullToRefresh();
                }
            }

            // If the total item count is zero and the previous isn't, assume the
            // list is invalidated and should be reset back to initial state
            if (totalItemCount < previousTotalItemCount) {
                this.currentPage = this.startingPageIndex;
                this.previousTotalItemCount = totalItemCount;
                if (totalItemCount == 0) {
                    this.loading = true;
                }
            }
            // If it’s still loading, we check to see if the dataset count has
            // changed, if so we conclude it has finished loading and update the current page
            // number and total item count.
            if (loading && (totalItemCount > previousTotalItemCount)) {
                loading = false;
                previousTotalItemCount = totalItemCount;
            }

            // If it isn’t currently loading, we check to see if we have breached
            // the visibleThreshold and need to reload more data.
            // If we do need to reload some more data, we execute onLoadMore to fetch the data.
            // threshold should reflect how many total columns there are too
            if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) {
                currentPage++;
                onLoadMore(currentPage, totalItemCount, view);
                loading = true;
            }
        }

        // Call this method whenever performing new searches
        public void resetState() {
            this.currentPage = this.startingPageIndex;
            this.previousTotalItemCount = 0;
            this.loading = true;
        }

        // Defines the process for actually loading more data based on page
        public abstract void onLoadMore(int page, int totalItemsCount, RecyclerView view);

        public abstract void doPullToRefresh();

    }

初始化回收站视图并将回滚站侦听器添加到回收站视图中：

scrollListener = new EndlessRecyclerViewScrollListener(llm) {
            @Override
            public void onLoadMore(int page, int totalItemsCount, RecyclerView view) {
                fetchNextTenRecords(page);
            }

            @Override
            public void doPullToRefresh() {
                swipeRefreshLayout.setEnabled(true);
            }
        };

Answer 4

使用import requests login_url = "https://www.editorialmanager.com/mind/default.aspx" login_data = {'username':'***','password':'***'} s = requests.Session() s.post(login_url,data=login_data) r = s.get('https://www.editorialmanager.com/mind/auth_pendSubmissions.asp?currentPage=1') rt = r.text result = rt.find('Under review') print(result) 和RecyclerView.OnScrollListener可以找到最后一个可见项目的索引。如果索引等于项目总数-1，则可以将其视为列表的末尾并加载下一页。

RecyclerView.LayoutManager