cleanMachine_android/app/src/main/res/layout/fragment_general_parameter.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/shallowblue"
    android:padding="@dimen/dp_5">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/rv_currency"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginRight="@dimen/dp_30"
            android:descendantFocusability="beforeDescendants"
            android:fastScrollEnabled="false"
            tools:ignore="MissingConstraints">

        </android.support.v7.widget.RecyclerView>
</LinearLayout>