Android设计支持库的菜单和Autohide FloatingActionButton

Question

我正在使用Android设计支持库,我想要一个通过滚动具有AutoHide的FloatingActionButton,

我的布局是:

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ScrollView
        android:id="@+id/scrollView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/LargeText" />
    </ScrollView>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_anchorGravity="bottom|right|end"
        app:layout_anchor="@id/scrollView"
        android:src="@drawable/abc_btn_rating_star_off_mtrl_alpha" />

</android.support.design.widget.CoordinatorLayout>

FloatingActionButton总是在滚动文本时显示,我想在滚动文本时自动隐藏它.

并且,我希望通过单击FloatingActionButton来获得FloatingActionButton菜单,如下所示:

Answer 1

通过滚动具有AutoHide的FloatingActionButton,

你必须使用android.support.v4.widget.NestedScrollView而不是ScrollView.您无法使用ScrollView.您必须使用NestedScrollView或实现NestedScrollingChild接口的视图,如RecyclerView.

要实现这种模式,您必须实现自定义Behavior.Googler发布了一个很好的代码,当用户向下滚动时会隐藏FAB,并在向上滚动时显示它.重用FloatingActionButton.Behavior用于隐藏/显示FAB以响应退出/进入的AppBarLayout的相同动画.

2015年7月18日更新

使用22.2.1,您只需使用预先构建的动画添加下面发布的代码即可.只要使用这样的类:(原始的源位置)

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, directTargetChild, target, nestedScrollAxes);
    }

    @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) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            child.hide();
        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            child.show();
        }
    }
}

然后,您可以使用以下方法将此行为应用于FAB:

<android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
     app:layout_behavior="com.support.android.designlibdemo.ScrollAwareFABBehavior" />

随着设计22.2.0:你要使用这样的类:(原始的源位置)

public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
    private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
    private boolean mIsAnimatingOut = false;

    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, directTargetChild, target, nestedScrollAxes);
    }

    @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 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            animateOut(child);
        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            animateIn(child);
        }
    }

    // Same animation that FloatingActionButton.Behavior uses to hide the FAB when the AppBarLayout exits
    private void animateOut(final FloatingActionButton button) {
        if (Build.VERSION.SDK_INT >= 14) {
            ViewCompat.animate(button).scaleX(0.0F).scaleY(0.0F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer()
                    .setListener(new ViewPropertyAnimatorListener() {
                        public void onAnimationStart(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
                        }

                        public void onAnimationCancel(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                        }

                        public void onAnimationEnd(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                            view.setVisibility(View.GONE);
                        }
                    }).start();
        } else {
            Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.fab_out);
            anim.setInterpolator(INTERPOLATOR);
            anim.setDuration(200L);
            anim.setAnimationListener(new Animation.AnimationListener() {
                public void onAnimationStart(Animation animation) {
                    ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
                }

                public void onAnimationEnd(Animation animation) {
                    ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                    button.setVisibility(View.GONE);
                }

                @Override
                public void onAnimationRepeat(final Animation animation) {
                }
            });
            button.startAnimation(anim);
        }
    }

    // Same animation that FloatingActionButton.Behavior uses to show the FAB when the AppBarLayout enters
    private void animateIn(FloatingActionButton button) {
        button.setVisibility(View.VISIBLE);
        if (Build.VERSION.SDK_INT >= 14) {
            ViewCompat.animate(button).scaleX(1.0F).scaleY(1.0F).alpha(1.0F)
                    .setInterpolator(INTERPOLATOR).withLayer().setListener(null)
                    .start();
        } else {
            Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.fab_in);
            anim.setDuration(200L);
            anim.setInterpolator(INTERPOLATOR);
            button.startAnimation(anim);
        }
    }
}

然后,您可以使用以下方法将此行为应用于FAB:

<android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
     app:layout_behavior="com.support.android.designlibdemo.ScrollAwareFABBehavior" />

当然,您可以更改此代码以获取您喜欢的模式.

并且,我希望通过单击FloatingActionButton来获得FloatingActionButton菜单,如下所示:

目前,原始FAB不支持此模式.您必须实现自定义代码才能实现它.