Detect when RecyclerView reaches the bottom most position while scrolling

后端 未结 11 1869
没有蜡笔的小新
没有蜡笔的小新 2020-11-29 19:56

I have this code for a RecyclerView.

    recyclerView = (RecyclerView)rootview.findViewById(R.id.fabric_recyclerView);
    recyclerView.setLayoutManager(layo         


        
11条回答
  •  一生所求
    2020-11-29 20:35

    Try This

    I have used above answers it runs always when you will go at the end of recycler view,

    If you want to check only one time whether it is on a bottom or not? Example:- If I have the list of 10 items whenever I go on the bottom it will display me and again if I scroll top to bottom it will not print again, and if you add more lists and you go there it will again display.

    Note:- Use this method when you deal with offset in hitting API

    1. Create a class named as EndlessRecyclerViewScrollListener

          import android.support.v7.widget.GridLayoutManager;
          import android.support.v7.widget.LinearLayoutManager;
          import android.support.v7.widget.RecyclerView;
          import android.support.v7.widget.StaggeredGridLayoutManager;
      
          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() {
          //        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 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);
      
          }
      
    2. use this class like this

           LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
              recyclerView.setLayoutManager(linearLayoutManager);
              recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener( linearLayoutManager) {
                  @Override
                  public void onLoadMore(int page, int totalItemsCount, RecyclerView view) {
                      Toast.makeText(getActivity(),"LAst",Toast.LENGTH_LONG).show();
                  }
              });
      

    Its running perfect at my end, commnent me if you are getting any issue

提交回复
热议问题