MpPreview/app/src/main/res/layout/fragment_camera2_raw.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:context=".Camera2RawFragment">

    <com.xypower.mppreview.AutoFitTextureView
        android:id="@+id/texture"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <Button
        android:id="@+id/takepic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="40dp"
        android:background="@mipmap/takepic"
        android:shadowColor="@null"
        android:text="拍照"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>