滚动时 FloatActionButton 不隐藏

Question

我试图在 Activity 中向下滚动时隐藏我的 FAB，但无法正常工作。为什么？？？片段标签内有带有 RecyclerView 的片段。

这是我的 Activity xml 代码：

<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activities.principal.PrincipalActivity">

<fragment
        android:id="@+id/PrincipalActivity_navHostFragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/principal_nav_graph" />

<com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/PrincipalActivity_bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorPrimary"
        app:itemIconTint="@drawable/bottom_navigation_colors"
        app:itemTextColor="@android:color/white"
        app:layout_anchor="@id/PrincipalActivity_navHostFragment"
        app:layout_anchorGravity="bottom"
        app:menu="@menu/bottom_navigation_menu_principal" />

<com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/PrincipalActivity_fabItensPedido"
        style="@style/Widget.MaterialComponents.FloatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="70dp"
        android:src="@drawable/ic_carrinho"
        app:backgroundTint="@color/colorAccent"
        app:fabSize="auto"
        app:layout_anchor="@id/PrincipalActivity_navHostFragment"
        app:layout_anchorGravity="bottom|end"
        app:layout_behavior=".utils.ScrollAnimationFAB" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

这是我在 FAB 按钮中使用的布局行为，但在 activity 中不起作用，仅在片段标签内的片段中起作用。

class ScrollAnimationFAB extends CoordinatorLayout.Behavior<FloatingActionButton> {

    public ScrollAnimationFAB(){
        super();
    }

    public ScrollAnimationFAB(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull FloatingActionButton child, @NonNull View directTargetChild, @NonNull View target, int axes, int type) {
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL ||
                super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target,
                        axes, ViewCompat.TYPE_TOUCH);
    }

    @Override
    public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull FloatingActionButton child, @NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type, @NonNull int[] consumed) {

        Log.v("Msg", "dyConsumed: " + dyConsumed + ", dyUnConsumed: " + dyUnconsumed);
        if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
            child.hide(new FloatingActionButton.OnVisibilityChangedListener() {
                @Override
                public void onHidden(FloatingActionButton fab) {
                    super.onHidden(fab);
                    fab.setVisibility(View.INVISIBLE);
                }
            });
        } else if (dyConsumed < 0 && dyUnconsumed == 0 && child.getVisibility() != View.VISIBLE) {
            child.show();
        }
    }
}

请帮帮我

Answer 1

浮动操作按钮为您提供了一种很好的方法fab.hide()

Answer 2

如果 FloatingActionButton 在 CoordinatorLayout 中 - 你应该使用下面的代码：

    CoordinatorLayout.LayoutParams p = (CoordinatorLayout.LayoutParams) playlist_FAB_start.getLayoutParams();
    p.setAnchorId(View.NO_ID);
    playlist_FAB_start.setLayoutParams(p);
    playlist_FAB_start.setVisibility(View.GONE);

Answer 3

我这样解决问题：

recyclerView =
            rootView.findViewById<RecyclerView>(R.id.recyclerView).apply {
                this.setHasFixedSize(true)
                this.layoutManager = LinearLayoutManager(activity?.baseContext)

                this.addOnScrollListener(object : RecyclerView.OnScrollListener() {
                    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                        if (dy > 0)
                            activity_fab.hide()
                        else
                            activity_fab.show()

                    }
                })
            }

FAB 视图在我的 activity 中。但是上面的这段代码在片段中。我在片段中这样称呼 FAB：(activity as AppCompatActivity).findViewById(R.id.activity_fab).

滚动时 FloatActionButton 不隐藏

FloatActionButton is not hiding when scrolling

android

floating-action-button

android-coordinatorlayout