相关疑难解决方法(0)

林使用FloatingActionButton从android.support.design.widget包:

<android.support.design.widget.FloatingActionButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:layout_marginBottom="20dp"
    android:layout_marginEnd="16dp"
    android:clickable="true"
    android:backgroundTint="@color/primaryColor"
    android:src="@drawable/ic_search_white_24dp"
    app:borderWidth="0dp"
    app:elevation="6dp"
    app:backgroundTint="@color/primaryColorDark"
    app:rippleColor="@color/accentColor" />

当列表视图向下滚动时是否可以将该按钮配置为隐藏动画,并在列表视图滚动到顶部时再次显示该按钮？

试图实现一个Floating Action Button隐藏在向下滚动的(FAB),并在向上滚动时显示.

我必须ScrollAwareFABBehavior.java管理它,并且它连接到XML中的FAB activity_main.问题: FAB隐藏在向下滚动,但在向上滚动时不再显示.我记录了该onNestedScroll方法,并在向下滚动时调用"调用滚动"和"调用隐藏"; 但是在FAB被隐藏之后,没有3x Log的

问题:为什么在FAB隐藏后向上滚动时FAB不显示.

ScrollAwareFABBehavior.java:

import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
    public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
        super();
    }

    @Override
    public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
                                       final View directTargetChild, final View target, final int nestedScrollAxes) {
        // Ensure we react to vertical scrolling
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, …