How to create Horizontal scroll bar fixed size and center align in android

UPDATE

Add a horizontal scroll bar to recyclerview , and set the trumb and bg

 <androidx.recyclerview.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:scrollbars="horizontal"
    android:scrollbarStyle="outsideInset"
    android:fadeScrollbars="false"
    android:overScrollMode="never"
    android:scrollbarSize="5dp"
    android:scrollbarThumbHorizontal="@drawable/aa_scrollbar"
    android:scrollbarTrackHorizontal="@drawable/aa_scrollbar_bg"
    />

aa_scrollbar.xml :

<?xml version="1.0" encoding="UTF-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 
    <item
        android:width="@dimen/dpi_80px"
        android:left="@dimen/dpi_20px"
        android:right="@dimen/dpi_20px">
        <shape>
            <corners android:radius="@dimen/dpi_10px" />
            <solid android:color="?attr/Theme_color" />
        </shape>
    </item>
 
</layer-list>

aa_scrollbar_bg.xml

<?xml version="1.0" encoding="UTF-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 
    <item
        android:left="@dimen/dpi_20px"
        android:right="@dimen/dpi_20px">
        <shape>
            <corners android:radius="@dimen/dpi_10px" />
            <solid android:color="@color/scrollbar_bg" />
        </shape>
    </item>
</layer-list>

could rejust the para like dpi_20px as you needed.

Add a horizontal scroll bar to recyclerview .May this help you.

   <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbars="horizontal"
        android:scrollbarStyle="outsideInset"
        android:fadeScrollbars="false"
        android:overScrollMode="never"
        android:scrollbarSize="5dp"
        android:scrollbarThumbHorizontal="#DF9797"
        android:scrollbarTrackVertical="#fff"
        />