android - 约束布局动画不起作用

由于某种原因，我无法使constraintset动画执行任何操作。调用代码没有任何反应。即使我更改tab的ID

private fun moveNavigationBall(tab: BottombarItemView) {
    val constraintSet = ConstraintSet()

    constraintSet.clone(cl_bottombar_view_main)
    constraintSet.connect(v_bottom_bar_circle_indicator.id, ConstraintSet.TOP, tab.id, ConstraintSet.TOP,0);
    constraintSet.connect(v_bottom_bar_circle_indicator.id, ConstraintSet.BOTTOM, tab.id, ConstraintSet.BOTTOM,0);
    constraintSet.connect(v_bottom_bar_circle_indicator.id, ConstraintSet.LEFT, tab.id, ConstraintSet.LEFT,0);
    constraintSet.connect(v_bottom_bar_circle_indicator.id, ConstraintSet.RIGHT, tab.id, ConstraintSet.RIGHT,0);
    constraintSet.applyTo(cl_bottombar_view_main)

    val transition = ChangeBounds()
    transition.interpolator = OvershootInterpolator()
    TransitionManager.beginDelayedTransition(cl_bottombar_view_main, transition)
}

按下按钮时调用。选项卡因按下哪个按钮而异。我想做的是将v_bottom_bar_circle_indicator移动到每个选项卡的中间

风景

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    android:id="@+id/cl_bottombar_view_main"
    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="wrap_content"
    xmlns:tools="http://schemas.android.com/tools"
    >

    <com.main.toucanmvp.mvp.components.bottombar.bottombaritem.BottombarItemView
        android:id="@+id/biv_home"
        android:layout_width="0dp"
        android:layout_height="56dp"
        app:bivBackground="@drawable/drawable_navigation_background_left"
        app:bivIcon="@drawable/ic_home"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/biv_search"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintHorizontal_chainStyle="spread"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <com.main.toucanmvp.mvp.components.bottombar.bottombaritem.BottombarItemView
        android:id="@+id/biv_search"
        android:layout_width="0dp"
        android:layout_height="56dp"
        app:bivIcon="@drawable/ic_search"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/biv_clan"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/biv_home"
        app:layout_constraintTop_toTopOf="parent"/>

    <com.main.toucanmvp.mvp.components.bottombar.bottombaritem.BottombarItemView
        android:id="@+id/biv_clan"
        android:layout_width="0dp"
        android:layout_height="56dp"
        app:bivIcon="@drawable/ic_crown"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/biv_news"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/biv_search"
        app:layout_constraintTop_toTopOf="parent"/>

    <com.main.toucanmvp.mvp.components.bottombar.bottombaritem.BottombarItemView
        android:id="@+id/biv_news"
        android:layout_width="0dp"
        android:layout_height="56dp"
        app:bivIcon="@drawable/ic_news"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/biv_profile"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/biv_clan"
        app:layout_constraintTop_toTopOf="parent"/>

    <com.main.toucanmvp.mvp.components.bottombar.bottombaritem.BottombarItemView
        android:id="@+id/biv_profile"
        android:layout_width="0dp"
        android:layout_height="56dp"
        app:bivBackground="@drawable/drawable_navigation_background_right"
        app:bivIcon="@drawable/ic_profile"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/biv_news"
        app:layout_constraintTop_toTopOf="parent"/>

    <FrameLayout
        android:id="@+id/v_bottom_bar_circle_indicator"
        android:layout_width="34dp"
        android:layout_height="34dp"
        android:background="@drawable/drawable_circle_navigation_bar"
        app:layout_constraintBottom_toBottomOf="@+id/biv_home"
        app:layout_constraintEnd_toEndOf="@+id/biv_home"
        app:layout_constraintStart_toStartOf="@+id/biv_home"
        app:layout_constraintTop_toTopOf="@+id/biv_home"/>
</android.support.constraint.ConstraintLayout>

最佳答案

首先，为了动画化约束的变化，您需要放置

constraintSet.applyTo(cl_bottombar_view_main)

后

TransitionManager.beginDelayedTransition(cl_bottombar_view_main, transition)

其次，在XML布局文件中，对要设置动画的视图（start）使用end和v_bottom_bar_circle_indicator约束，但是在代码中，您使用的是ConstraintSet.LEFT和ConstraintSet.RIGHT，这是不同的。您需要将它们分别更改为ConstraintSet.START和ConstraintSet.END。

第三件事，在这种情况下可能会或可能无关紧要，是您将0的边距设置为每个connect()函数的最后一个参数。 ConstraintSet文档说，边距必须为正数，因此将其设置为0时可能无法达到预期的效果。我建议在这种情况下使用不带margin参数的签名。