我的布局有问题,我创建了带有 RecyclerView 的 SwipeRefreshLayout 。 在 android 4.2.2+ 中一切都工作良好,但在 andorid 2.3.4 中我无法向上滚动,因为在 RecyclerView 中的任何位置它都会刷新,我必须向下滚动然后向上滚动。
这是我的代码:
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/forum_swipe_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LVP"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center" />
</android.support.v4.widget.SwipeRefreshLayout>
我发现了这个问题:https://code.google.com/p/android/issues/detail?id=78191但没有解决方案。 知道如何解决吗?
重写RecyclerView的方法
OnScrollStateChanged
mRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
// TODO Auto-generated method stub
//super.onScrollStateChanged(recyclerView, newState);
try {
int firstPos = mLayoutManager.findFirstCompletelyVisibleItemPosition();
if (firstPos > 0) {
mSwipeRefreshLayout.setEnabled(false);
} else {
mSwipeRefreshLayout.setEnabled(true);
if(mRecyclerView.getScrollState() == 1)
if(mSwipeRefreshLayout.isRefreshing())
mRecyclerView.stopScroll();
}
}catch(Exception e) {
Log.e(TAG, "Scroll Error : "+e.getLocalizedMessage());
}
}
检查滑动刷新是否正在刷新并尝试向上滚动然后出现错误,因此当滑动刷新正在进行时我尝试执行此操作
mRecyclerView.stopScroll();
我使用以下代码修复了向上滚动问题:
private RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
LinearLayoutManager manager = ((LinearLayoutManager)recyclerView.getLayoutManager());
boolean enabled =manager.findFirstCompletelyVisibleItemPosition() == 0;
pullToRefreshLayout.setEnabled(enabled);
}
};
然后您需要使用
setOnScrollListener
或 addOnScrollListener
,具体取决于您是否有一个或多个听众。
不幸的是,这是一个已知问题,将在未来版本中修复。
https://code.google.com/p/android/issues/detail?id=78191
同时,如果您需要紧急修复,请覆盖
canChildScrollUp
中的 SwipeRefreshLayout.java
并致电 recyclerView.canScrollVertically(mTarget, -1)
。因为 canScrollVertically
是在姜饼之后添加的,所以您还需要复制该方法并在 recyclerview 中实现。
或者,如果您使用 LinearLayoutManager,则可以调用
findFirstCompletelyVisibleItemPosition
。
抱歉给您带来不便。
您可以根据recyclerview的滚动能力禁用/启用刷新布局
public class RecyclerSwipeRefreshHelper extends RecyclerView.OnScrollListener{
private static final int DIRECTION_UP = -1;
private final SwipeRefreshLayout refreshLayout;
public RecyclerSwipeRefreshHelper(
SwipeRefreshLayout refreshLayout) {
this.refreshLayout = refreshLayout;
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
refreshLayout.setEnabled((recyclerView.canScrollVertically(DIRECTION_UP)));
}
}
您可以像这样重写 SwipeRefreshLayout 中的 canChildScrollUp() 方法:
public boolean canChildScrollUp() {
if (mTarget instanceof RecyclerView) {
final RecyclerView recyclerView = (RecyclerView) mTarget;
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
int position = ((LinearLayoutManager) layoutManager).findFirstCompletelyVisibleItemPosition();
return position != 0;
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
int[] positions = ((StaggeredGridLayoutManager) layoutManager).findFirstCompletelyVisibleItemPositions(null);
for (int i = 0; i < positions.length; i++) {
if (positions[i] == 0) {
return false;
}
}
}
return true;
} else if (android.os.Build.VERSION.SDK_INT < 14) {
if (mTarget instanceof AbsListView) {
final AbsListView absListView = (AbsListView) mTarget;
return absListView.getChildCount() > 0
&& (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
.getTop() < absListView.getPaddingTop());
} else {
return mTarget.getScrollY() > 0;
}
} else {
return ViewCompat.canScrollVertically(mTarget, -1);
}
}
基于@wrecker的回答(https://stackoverflow.com/a/32318447/7508302)。
在Kotlin中我们可以使用扩展方法。所以:
class RecyclerViewSwipeToRefresh(private val refreshLayout: SwipeToRefreshLayout) : RecyclerView.OnScrollListener() {
companion object {
private const val DIRECTION_UP = -1
}
override fun onScrolled(recyclerView: RecyclerView?, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
refreshLayout.isEnabled = !(recyclerView?.canScrollVertically(DIRECTION_UP) ?: return)
}
}
让我们向 RecyclerView 添加扩展方法,以轻松将此修复应用于 RV。
fun RecyclerView.fixSwipeToRefresh(refreshLayout: SwipeRefreshLayout): RecyclerViewSwipeToRefresh {
return RecyclerViewSwipeToRefresh(refreshLayout).also {
this.addOnScrollListener(it)
}
}
现在,我们可以使用以下方法修复recyclerView:
recycler_view.apply {
...
fixSwipeToRefresh(swipe_container)
...
}
以下代码对我有用,请确保将其放置在 binding.recycler_view.setOnRefreshListener{} 方法下方。
binding.swipeToRefreshLayout.setOnChildScrollUpCallback(object : SwipeRefreshLayout.OnChildScrollUpCallback {
override fun canChildScrollUp(parent: SwipeRefreshLayout, child: View?): Boolean {
if (binding.rvDiscover != null) {
return binding.recyclerView.canScrollVertically(-1)
}
return false
}
})