Android 自定义behavior实现上滑屏幕隐藏底部

BottomNavigationView动画实现

最新推荐文章于 2024-12-20 02:38:52 发布

原创最新推荐文章于 2024-12-20 02:38:52 发布 · 1.3k 阅读

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CC 4.0 BY-SA版权

本文详细介绍如何使用CoordinatorLayout和Behavior在Android中实现BottomNavigationView的上下滑动隐藏与显示动画效果，通过自定义BottomNavigationBehavior，利用ObjectAnimator对translationY属性进行动画处理。

直接上代码：

1.引用

<android.support.design.widget.CoordinatorLayout

android:layout_width="match_parent"

android:layout_height="match_parent">

<include layout="@layout/toolbar"/>

<include layout="@layout/container"/>

<android.support.design.widget.BottomNavigationView

android:id="@+id/bottom_navigation"

style="@style/Widget.Design.BottomNavigationView"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:layout_gravity="bottom"

android:background="@color/viewBackground"

app:elevation="16dp"

app:itemIconTint="@drawable/nav_item_color_state"

app:itemTextColor="@drawable/nav_item_color_state"

app:layout_behavior="com.idengyun.widget.BottomNavigationBehavior"

app:menu="@menu/bottom_navigation_main"/>





2.关键类
public class BottomNavigationBehavior extends CoordinatorLayout.Behavior<View> {
    private ObjectAnimator outAnimator, inAnimator;
    public BottomNavigationBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    // 垂直滑动
    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
    }

    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) {
        if (dy > 0) {// 上滑隐藏
            if (outAnimator == null) {
                outAnimator = ObjectAnimator.ofFloat(child, "translationY", 0, child.getHeight());
                outAnimator.setDuration(200);
            }
            if (!outAnimator.isRunning() && child.getTranslationY() <= 0) {
                outAnimator.start();
            }
        } else if (dy < 0) {// 下滑显示
            if (inAnimator == null) {
                inAnimator = ObjectAnimator.ofFloat(child, "translationY", child.getHeight(), 0);
                inAnimator.setDuration(200);
            }
            if (!inAnimator.isRunning() && child.getTranslationY() >= child.getHeight()) {
                inAnimator.start();
            }
        }
    }
}