Android - 约束布局 - 如何将视图对齐居中于其他视图的边缘？

Question

我想构建一个这样的布局:

在约束布局中,有一个像横幅一样的图像视图,然后有一个卡片与横幅的下边缘居中对齐,然后有另一个图像视图与卡片的上边缘对齐.

我面临的问题是,当与卡对齐时,第二个图像视图(绿色一个)进入后台而不是停留在前景中.

这是xml,

<android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            app:layout_collapseMode="parallax"
            android:paddingBottom="@dimen/padding_10">

            <ImageView
                android:id="@+id/imageView_jobBackdrop_jobDetails"
                android:layout_width="match_parent"
                android:layout_height="175dp"
                android:fitsSystemWindows="true"
                android:scaleType="centerCrop"
                android:src="@drawable/backdrop_job_details"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_collapseMode="parallax"/>

            <ImageView
                android:id="@+id/imageView_companyLogo_jobDetails"
                android:layout_width="75dp"
                android:layout_height="75dp"
                android:fitsSystemWindows="true"
                app:layout_collapseMode="parallax"
                app:layout_constraintBottom_toTopOf="@+id/cardView_jobHeader_jobDetails"
                app:layout_constraintEnd_toEndOf="@id/cardView_jobHeader_jobDetails"
                app:layout_constraintStart_toStartOf="@id/cardView_jobHeader_jobDetails"
                app:layout_constraintTop_toTopOf="@+id/cardView_jobHeader_jobDetails" />

            <android.support.v7.widget.CardView
                android:id="@+id/cardView_jobHeader_jobDetails"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginBottom="24dp"
                android:layout_marginEnd="16dp"
                android:layout_marginStart="16dp"
                app:layout_constraintBottom_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"
                app:layout_constraintVertical_bias="0.5">

                <android.support.constraint.ConstraintLayout
                    android:id="@+id/parent"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:id="@+id/textView_jobTitle_jobDetails"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginEnd="16dp"
                        android:layout_marginStart="16dp"
                        android:layout_marginTop="32dp"
                        android:gravity="center"
                        android:text="Fresher Software Developer Job. Urgent Openning. Angular Js, HTML, JavaScript, CSS"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintTop_toTopOf="parent" />

                </android.support.constraint.ConstraintLayout>
            </android.support.v7.widget.CardView>
        </android.support.constraint.ConstraintLayout>

Answer 1

试试这个:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="20dp">

    <android.support.v7.widget.CardView
        android:id="@+id/card_1"
        android:layout_width="0dp"
        android:layout_height="200dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <android.support.v7.widget.CardView
        android:id="@+id/card_2"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginBottom="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="0dp"
        app:cardBackgroundColor="#69F"
        app:layout_constraintBottom_toBottomOf="@+id/card_1"
        app:layout_constraintLeft_toLeftOf="@+id/card_1"
        app:layout_constraintRight_toRightOf="@+id/card_1"
        app:layout_constraintTop_toBottomOf="@+id/card_1" />

</android.support.constraint.ConstraintLayout>

说明: - 这是因为这四行

以下行将蓝色CardView设置在White CardView底边的中心.

<!-- top constraint is set to bottom of White CardView -->
app:layout_constraintTop_toBottomOf="@+id/card_1"

<!-- bottom constraint is set to bottom of White CardView -->
app:layout_constraintBottom_toBottomOf="@+id/card_1"

以下行设置蓝色CardView水平居中

<!-- left constraint is set to left of White CardView -->
app:layout_constraintLeft_toLeftOf="@+id/card_1"

<!-- right constraint is set to right of White CardView -->
app:layout_constraintRight_toRightOf="@+id/card_1"

Answer 2

试试下面：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    app:layout_collapseMode="parallax">


    <ImageView
        android:id="@+id/imageView_jobBackdrop_jobDetails"
        android:layout_width="match_parent"
        android:layout_height="175dp"
        android:fitsSystemWindows="true"
        android:scaleType="centerCrop"
        android:background="@android:color/white"
        app:layout_collapseMode="parallax"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:background="@android:color/black"
        app:layout_constraintBottom_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintEnd_toEndOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintStart_toStartOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintTop_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"  />

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="75dp"
        android:layout_height="75dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:background="@android:color/darker_gray"
        app:layout_constraintBottom_toTopOf="@+id/imageView2"
        app:layout_constraintEnd_toEndOf="@+id/imageView2"
        app:layout_constraintStart_toStartOf="@+id/imageView2"
        app:layout_constraintTop_toTopOf="@+id/imageView2"  />


</android.support.constraint.ConstraintLayout>