android - 第一次触摸时 MotionLayout 视觉故障

Question

我正在使用 com.android.support.constraint:constraint-layout:2.0.0-alpha2 包中的新 MotionLayout。

但我目睹了第一次触摸屏幕时发生的视觉故障。我已经为 dragDirection="dragDown" 实现了 OnSwipe，但是如果我在任何其他操作之前向上拖动，它会显示动画的结束状态。不幸的是，我无法上传可以显示它的 GIF，因为它太大了。所以我附上所有代码:

编辑附加视频 - https://youtu.be/CYZy_Kt_LH0

scene_03.xml

<?xml version="1.0" encoding="utf-8"?>
<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:motion="http://schemas.android.com/apk/res-auto">

  <Transition
      motion:constraintSetStart="@+id/start"
      motion:constraintSetEnd="@+id/end"
      motion:duration="10000">

    <OnSwipe
        motion:touchAnchorId="@+id/hpImage"
        motion:touchAnchorSide="bottom"
        motion:dragDirection="dragDown" />
  </Transition>

  <ConstraintSet android:id="@+id/start">
    <Constraint
        android:id="@+id/hpImage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="centerCrop"
        android:adjustViewBounds="true"
        motion:layout_constraintStart_toStartOf="parent"
        motion:layout_constraintEnd_toEndOf="parent"
        motion:layout_constraintTop_toTopOf="parent"
        />

    <Constraint
        android:id="@+id/tvHp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="12dp"
        android:layout_marginBottom="12dp"
        android:textSize="24sp"
        android:scaleX="1"
        android:scaleY="1"
        android:text="Harry Potter"
        android:textColor="#fff"
        motion:layout_constraintStart_toStartOf="@+id/hpImage"
        motion:layout_constraintBottom_toBottomOf="@+id/hpImage"
        />

  </ConstraintSet>

  <ConstraintSet android:id="@+id/end">
    <Constraint
        android:id="@+id/hpImage"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:scaleType="centerCrop"
        android:adjustViewBounds="true"
        android:visibility = "invisible"
        motion:layout_constraintStart_toStartOf="parent"
        motion:layout_constraintEnd_toEndOf="parent"
        motion:layout_constraintTop_toTopOf="parent"
      >
    </Constraint>

    <Constraint
        android:id="@+id/tvHp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="0dp"
        android:layout_marginBottom="0dp"
        android:scaleX="0.7"
        android:scaleY="0.7"
        android:gravity="center"
        android:text="Harry Potter"
        android:textColor="#fff"
        motion:layout_constraintStart_toStartOf="@+id/hpImage"
        motion:layout_constraintTop_toTopOf="@+id/hpImage"
        motion:layout_constraintBottom_toBottomOf="@+id/hpImage"
        />
  </ConstraintSet>

</MotionScene>

activity_test.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.motion.MotionLayout 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/motionLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutDescription="@xml/scene_03"
    android:background="@color/whiteSecondary"
    tools:showPaths="true">

  <View
      android:id="@+id/colorBackground"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      app:layout_constraintStart_toStartOf="@+id/hpImage"
      app:layout_constraintEnd_toEndOf="@+id/hpImage"
      app:layout_constraintTop_toTopOf="@+id/hpImage"
      app:layout_constraintBottom_toBottomOf="@+id/hpImage"
      android:background="@color/colorPrimary"
      />

  <ImageView
      android:id="@+id/hpImage"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:src="@drawable/hp"
      android:scaleType="centerCrop"
      android:adjustViewBounds="true"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintTop_toTopOf="parent"
      />

  <TextView
      android:id="@+id/tvHp"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginStart="12dp"
      android:layout_marginBottom="12dp"
      android:textSize="24sp"
      android:maxLines="1"
      android:text="Harry Potter"
      android:textColor="#fff"
      app:layout_constraintStart_toStartOf="@+id/hpImage"
      app:layout_constraintBottom_toBottomOf="@+id/hpImage"
      />

</android.support.constraint.motion.MotionLayout>

Answer 1

约束布局的 alpha 3 版本中的可能修复 https://androidstudio.googleblog.com/2018/12/constraintlayout-200-alpha-3.html