View is pushed out of its constraints in ConstraintLayout

问题

I have a ConstraintLayout with an ImageView and 3 chained TextViews with a spread_inside chain style:

<android.support.design.card.MaterialCardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/space_normal"
        android:paddingEnd="@dimen/space_normal"
        android:paddingStart="@dimen/space_normal"
        android:paddingTop="@dimen/space_big">

        <ImageView
            android:id="@+id/ivImage"
            android:layout_width="@dimen/feed_list_image_size"
            android:layout_height="@dimen/feed_list_image_size"
            android:layout_marginBottom="@dimen/space_normal"
            android:contentDescription="@null"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.0"
            tools:src="@color/debug_3" />

        <TextView
            android:id="@+id/tvTitle"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/space_normal"
            android:ellipsize="end"
            android:maxLines="3"
            android:textSize="@dimen/text_size_big"
            app:layout_constraintBottom_toTopOf="@+id/tvContent"
            app:layout_constraintEnd_toStartOf="@+id/ivImage"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_chainStyle="spread_inside"
            app:textAllCaps="true"
            tools:text="@tools:sample/lorem" />

        <TextView
            android:id="@+id/tvContent"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginBottom="@dimen/space_big"
            android:layout_marginTop="@dimen/space_normal"
            android:ellipsize="end"
            android:maxLines="4"
            android:textColor="@color/gray_600"
            android:textSize="@dimen/text_size_normal"
            app:layout_constraintBottom_toTopOf="@+id/tvDate"
            app:layout_constraintEnd_toEndOf="@+id/tvTitle"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/tvTitle"
            tools:text="@tools:sample/lorem/random" />

        <TextView
            android:id="@+id/tvDate"
            style="@style/AppTheme.ItemFeedList.Date"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="@dimen/space_normal"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/tvContent"
            tools:text="@tools:sample/date/hhmm" />

    </android.support.constraint.ConstraintLayout>

</android.support.design.card.MaterialCardView>

This renders a nice and flexible layout in the editor:

But sometimes the top view is "pushed" out of its contraints so the text rendering is wrong (clipped). It's wierd because spread_inside chain style should inflate and narrow the middle view. From the Layout Inspector:

What's the wrong with it?

回答1:

A change made in version 1.1 of ConstraintLayout may help you. Try setting app:layout_constrainedHeight=”true” on your troublesome TextView. From the developer guide for ConstraintLayout:

WRAP_CONTENT : enforcing constraints (Added in 1.1)

If a dimension is set to WRAP_CONTENT, in versions before 1.1 they will be treated as a literal dimension -- meaning, constraints will not limit the resulting dimension. While in general this is enough (and faster), in some situations, you might want to use WRAP_CONTENT, yet keep enforcing constraints to limit the resulting dimension. In that case, you can add one of the corresponding attribute:

app:layout_constrainedWidth=”true|false”
app:layout_constrainedHeight=”true|false”

来源：https://stackoverflow.com/questions/50725392/view-is-pushed-out-of-its-constraints-in-constraintlayout