<?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:id="@+id/container" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/testtap" android:textSize="30sp" app:layout_constraintHorizontal_bias="0.501" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="0dp" android:layout_marginEnd="13dp" android:layout_marginLeft="8dp" android:layout_marginRight="13dp" android:layout_marginStart="8dp" android:onClick="onClickButton" android:text="Activity" app:layout_constraintBaseline_toBaselineOf="@+id/button3" app:layout_constraintEnd_toStartOf="@+id/button3" app:layout_constraintHorizontal_chainStyle="packed" app:layout_constraintStart_toStartOf="parent" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="0dp" android:layout_marginTop="12dp" android:onClick="ChangeFragment" android:text="MainFragment" app:layout_constraintEnd_toStartOf="@+id/button4" app:layout_constraintStart_toEndOf="@+id/button2" app:layout_constraintTop_toBottomOf="@+id/textView" /> <Button android:id="@+id/button4" android:layout_width="wrap_content" android:layout_height="0dp" android:onClick="ChangeFragment" android:text="SubFragment" app:layout_constraintBaseline_toBaselineOf="@+id/button3" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toEndOf="@+id/button3" /> <fragment android:id="@+id/fragment_place" android:name="com.example.nitta_lab_2.myapplication.MainFragment" android:layout_width="0dp" android:layout_height="0dp" android:layout_marginBottom="8dp" android:layout_marginEnd="8dp" android:layout_marginLeft="8dp" android:layout_marginRight="8dp" android:layout_marginStart="8dp" android:layout_marginTop="8dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/button3" app:layout_constraintVertical_bias="0.0" /> </android.support.constraint.ConstraintLayout>