![](/img/trans.png)
[英]Android RecyclerView - StaggeredGridLayoutManager messes up width when scrolling
[英]Pagination with staggeredGridLayoutManager and recyclerView
您好,我需要使用 staggeredGridLayoutManager 使用 recyclerview 进行无限滚动(分页)。 分页正在工作,但问题是onLoadMore()
函数在滚动时被调用了很多次,这导致了问题,这是我的代码:
newSearchAdapter = new NewSearchAdapter(getActivity(), gridData);
StaggeredGridLayoutManager mLayoutManager;
mLayoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
mLayoutManager.setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_NONE);
rv_NewProfilesGrid.setLayoutManager(mLayoutManager);
rv_NewProfilesGrid.setAdapter(newSearchAdapter);
rv_NewProfilesGrid.addOnScrollListener(new EndlessRecyclerOnScrollListenerStaggeredLayoutmanager(mLayoutManager) {
@Override
public void onLoadMore(int current_page) {
//calling the api
}
});
这是我的滚动监听器
我认为这里的问题在于getFirstVisibleItems()
函数,因为使用GridLayoutManger或LinearLayoutManager它返回一个整数,但使用StaggeredLayout它返回一个 int 数组,所以我做了以下操作:
public abstract class EndlessRecyclerOnScrollListenerStaggeredLayoutmanager extends RecyclerView.OnScrollListener {
public static String TAG = EndlessRecyclerOnScrollListenerStaggeredLayoutmanager.class.getSimpleName();
private int scrolledDistance = 0;
private boolean controlsVisible = false;
private boolean loading = true; // True if we are still waiting for the last set of data to load.
private int visibleThreshold = 5; // The minimum amount of items to have below your current scroll position before loading more.
public static boolean loadOneTime = false;
private int pastVisibleItems, visibleItemCount, totalItemCount,previousTotal;
private int current_page = 1;
private StaggeredGridLayoutManager mStaggeredGridLayoutManager;
public EndlessRecyclerOnScrollListenerStaggeredLayoutmanager(StaggeredGridLayoutManager staggeredGridLayoutManager) {
this.mStaggeredGridLayoutManager = staggeredGridLayoutManager;
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
visibleItemCount = recyclerView.getChildCount();
totalItemCount = mStaggeredGridLayoutManager.getItemCount();
int[] firstVisibleItems = null;
firstVisibleItems = mStaggeredGridLayoutManager.findFirstVisibleItemPositions(firstVisibleItems);
if (firstVisibleItems != null && firstVisibleItems.length > 0) {
pastVisibleItems = firstVisibleItems[0];
}
if (loading) {
if ((visibleItemCount + pastVisibleItems) >= totalItemCount) {
loading = false;
previousTotal = totalItemCount;
}
}
if (!loading && (totalItemCount - visibleItemCount)
<= (pastVisibleItems + visibleThreshold)) {
// End has been reached
// Do something
current_page++;
loadOneTime=false;
onLoadMore(current_page);
loading = true;
}
if (scrolledDistance > 1 && controlsVisible) {
controlsVisible = false;
scrolledDistance = 0;
} else if (scrolledDistance < -1 && !controlsVisible) {
controlsVisible = true;
scrolledDistance = 0;
}
if ((controlsVisible && dy > 0) || (!controlsVisible && dy < 0)) {
scrolledDistance += dy;
}
}
public abstract void onLoadMore(int current_page);
}
尝试这个。 我从堆栈溢出的答案中借用了它并借用了另一个答案并将它们结合起来,我终于解决了它。
import android.util.Log
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.StaggeredGridLayoutManager
abstract class PaginationScrollListener constructor() :
RecyclerView.OnScrollListener() {
private lateinit var mLayoutManager: RecyclerView.LayoutManager
constructor(layoutManager: GridLayoutManager) : this() {
this.mLayoutManager = layoutManager
}
constructor(layoutManager: StaggeredGridLayoutManager) : this() {
this.mLayoutManager = layoutManager
}
constructor(layoutManager: LinearLayoutManager) : this() {
this.mLayoutManager = layoutManager
}
/*
Method gets callback when user scroll the search list
*/
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
val visibleItemCount = mLayoutManager.childCount
val totalItemCount = mLayoutManager.itemCount
var firstVisibleItemPosition = 0
when (mLayoutManager) {
is StaggeredGridLayoutManager -> {
val firstVisibleItemPositions =
(mLayoutManager as StaggeredGridLayoutManager).findFirstVisibleItemPositions(null)
// get maximum element within the list
firstVisibleItemPosition = firstVisibleItemPositions[0]
}
is GridLayoutManager -> {
firstVisibleItemPosition =
(mLayoutManager as GridLayoutManager).findFirstVisibleItemPosition()
}
is LinearLayoutManager -> {
firstVisibleItemPosition =
(mLayoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
}
}
if (!isLoading && !isLastPage) {
if (visibleItemCount + firstVisibleItemPosition >= totalItemCount
&& firstVisibleItemPosition >= 0
) {
Log.i(TAG, "Loading more items")
loadMoreItems()
}
}
}
protected abstract fun loadMoreItems()
abstract val isLastPage: Boolean
abstract val isLoading: Boolean
companion object {
private val TAG = PaginationScrollListener::class.java.simpleName
}
}
并以这种方式在您的回收站视图中使用它
rvCategoryProducts.addOnScrollListener(object :
PaginationScrollListener(layoutManager) {
override fun loadMoreItems() {
vm.isLoading = true
vm.currentPage++
GlobalScope.launch {
vm.getCategoryProductByCatId(vm.id, vm.currentPage)
}
}
override val isLastPage: Boolean
get() = vm.isLastPage
override val isLoading: Boolean
get() = vm.isLoading
})
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.