MotionLayout第一次触摸时出现视觉故障

Question

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

但我亲眼目睹了第一次触摸屏幕时出现的视觉故障。我已经为dragDirection="dragDown"实现了OnSwipe，但如果我在执行任何其他操作之前进行向上拖动，它将显示动画的结束状态。不幸的是，我无法上传GIF来显示它，因为它太大了。所以我附上了所有的代码：

编辑附加视频-https://youtu.be/CYZy_Kt_LH0

场景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

在constraintlayout的alpha 3版本中可能的修复https://androidstudio.googleblog.com/2018/12/constraintlayout-200-alpha-3.html