Android GridView 滑动条设置一直显示状态(推荐)

<GridView
     android:id="@+id/picture_grid"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:columnWidth="100dp"
     android:numColumns="auto_fit" 
     android:gravity="center"
     android:verticalSpacing="8dp" 
     android:horizontalSpacing="10dp" 
     android:stretchMode="columnWidth"
     android:fadeScrollbars="false" />

    android:fadeScrollbars="false"