onNestedScroll仅调用一次 [英] onNestedScroll called only once
本文介绍了onNestedScroll仅调用一次的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我上课
public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
super();
}
public ScrollAwareFABBehavior() {
super();
}
@Override
public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,final View directTargetChild, final View target, final int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
}
@Override
public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,final View target, final int dxConsumed, final int dyConsumed,final int dxUnconsumed, final int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
child.show();
}
}
}
问题在于当我向上滚动一个recyclerview时,onNestedScroll仅被调用一次,因此fab隐藏并且不再显示.这是我正在使用的布局
the problem is that onNestedScroll is called only once when I scroll up a recyclerview, so the fab is hiding and never shows again. Here is layout I am using
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/refresh_layout"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/list"
app:layoutManager="@string/vertical_linear_layout_manager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.v4.widget.SwipeRefreshLayout>
<android.support.design.widget.FloatingActionButton
android:id="@+id/add"
android:layout_width="wrap_content"
app:layout_behavior="mypackagename.util.ScrollAwareFABBehavior"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
app:useCompatPadding="true"
android:layout_margin="16sp"
android:src="@drawable/ic_add"/>
</android.support.design.widget.CoordinatorLayout>
我的支持库版本是25.1.0
My support libraries version is 25.1.0
推荐答案
我使用以下代码解决了将可见性从GONE更改为INVISIBLE的问题.
I solved the problem changing the visibility from GONE to INVISIBLE with the following code.
@Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed,
dyUnconsumed);
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
child.hide(new FloatingActionButton.OnVisibilityChangedListener() {
@Override
public void onShown(FloatingActionButton fab) {
super.onShown(fab);
}
@Override
public void onHidden(FloatingActionButton fab) {
super.onHidden(fab);
fab.setVisibility(View.INVISIBLE);
}
});
} else if (dyConsumed <= 0 && child.getVisibility() != View.VISIBLE) {
child.show();
}
}
这篇关于onNestedScroll仅调用一次的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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