ConstraintLayout CardView

Question

尝试在TextView和CardView之间建立基线时遇到问题。出于不稳定原因，尝试将其他视图作为基准的视图继续进行。

请帮助我理解问题的原因。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <com.integretrans.driver.ui.custom.TextViewRobotoBold
        android:id="@+id/semitrailler"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/semitrailer_change"
        android:textColor="@color/layout_text_color"
        android:textSize="@dimen/_10ssp"
        app:layout_constraintBottom_toTopOf="@+id/guideline19" />

    <android.support.v7.widget.CardView
        android:id="@+id/driver_card"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_marginEnd="8dp"
        app:cardElevation="3dp"
        app:cardUseCompatPadding="true"
        app:layout_constraintBaseline_toBaselineOf="@+id/semitrailler"
        app:layout_constraintBottom_toTopOf="@+id/guideline19"
        app:layout_constraintEnd_toEndOf="parent">

        <Spinner
            android:id="@+id/driver_list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/spinner_arrow"
            android:dropDownWidth="wrap_content" />
    </android.support.v7.widget.CardView>

    <android.support.constraint.Guideline
        android:id="@+id/guideline19"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.41" />

</android.support.constraint.ConstraintLayout>