如何在约束布局中均匀放置基准线下方的按钮

Question

my screenshot; constraint layout

如何将右侧的按钮放置在191导轨下方？

下面是XML：

source code xml

Answer 1

<?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"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="81dp">

    <EditText
        android:id="@+id/result"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:ems="10"
        android:inputType="numberSigned"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:layout_constraintLeft_creator="1"
        tools:layout_constraintTop_creator="1" />

    <Button
        android:id="@+id/button0"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="0"
        app:layout_constraintLeft_toRightOf="@+id/comma"
        app:layout_constraintTop_toTopOf="@+id/comma" />

    <Button
        android:id="@+id/button2"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="2"
        app:layout_constraintLeft_toRightOf="@+id/button1"
        app:layout_constraintTop_toTopOf="@+id/button1" />

    <Button
        android:id="@+id/button3"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="3"
        app:layout_constraintLeft_toRightOf="@+id/button2"
        app:layout_constraintTop_toBottomOf="@+id/button5" />

    <Button
        android:id="@+id/button4"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="4"
        app:layout_constraintRight_toLeftOf="@+id/button8"
        app:layout_constraintTop_toBottomOf="@+id/button7" />

    <Button
        android:id="@+id/button5"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="5"
        app:layout_constraintLeft_toRightOf="@+id/button4"
        app:layout_constraintTop_toBottomOf="@+id/button7" />

    <Button
        android:id="@+id/button6"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="6"
        app:layout_constraintLeft_toRightOf="@+id/button5"
        app:layout_constraintTop_toBottomOf="@+id/button8" />

    <Button
        android:id="@+id/button7"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginBottom="311dp"
        android:layout_marginLeft="8dp"
        android:text="7"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        tools:layout_constraintTop_creator="1" />

    <Button
        android:id="@+id/button8"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="8"
        app:layout_constraintLeft_toRightOf="@+id/button7"
        app:layout_constraintTop_toTopOf="@+id/button7" />

    <Button
        android:id="@+id/button9"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="9"
        app:layout_constraintLeft_toRightOf="@+id/button8"
        app:layout_constraintTop_toTopOf="@+id/button8" />

    <Button
        android:id="@+id/button1"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="1"
        app:layout_constraintRight_toLeftOf="@+id/button5"
        app:layout_constraintTop_toBottomOf="@+id/button4" />

    <Button
        android:id="@+id/comma"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text=","
        app:layout_constraintRight_toRightOf="@+id/button1"
        app:layout_constraintTop_toBottomOf="@+id/button1" />

    <Button
        android:id="@+id/equal"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="="
        app:layout_constraintLeft_toRightOf="@+id/button0"
        app:layout_constraintTop_toBottomOf="@+id/button2" />

    <Button
        android:id="@+id/del"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:text="DEL"
        app:layout_constraintBottom_toTopOf="@+id/divide"
        app:layout_constraintLeft_toRightOf="@+id/equal"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/guideline" />

    <Button
        android:id="@+id/divide"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:text="÷"
        app:layout_constraintBottom_toTopOf="@+id/multiply"
        app:layout_constraintLeft_toRightOf="@+id/equal"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/del" />

    <Button
        android:id="@+id/multiply"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:text="x"
        app:layout_constraintBottom_toTopOf="@+id/subtract"
        app:layout_constraintLeft_toRightOf="@+id/equal"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/divide" />

    <Button
        android:id="@+id/subtract"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:text="-"
        app:layout_constraintBottom_toTopOf="@+id/add"
        app:layout_constraintLeft_toRightOf="@+id/equal"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/multiply" />

    <Button
        android:id="@+id/add"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:text="+"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toRightOf="@+id/equal"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/subtract" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="191dp" />

</android.support.constraint.ConstraintLayout>