HarmonyOS RelativeContainer组件

RelativeContainer() {
  Image($r('app.media.ic_book_detail_edge')).width(15).alignRules({
    top:{anchor:'iv_book_cover',align:VerticalAlign.Top},
    bottom:{anchor:'iv_book_cover',align:VerticalAlign.Bottom},
    right:{anchor:'iv_book_cover',align:HorizontalAlign.End}
  }).margin({top:8,right:-8}).id('iv_book_detail_edge')
  Image("").width(157).height(174).alt($r('app.media.asc'))
    .alignRules({
      top:{anchor:'rl_book_details_layout',align:VerticalAlign.Top},
      left:{anchor:'rl_book_details_layout',align:HorizontalAlign.Start}
    }).borderRadius(6).margin({left:42,top:-15}).id("iv_book_cover")
}
.backgroundImage($r('app.media.bg_wordcard')).backgroundImageSize(ImageSize.Cover)
.width('100%')
.height('100%')

如何实现iv_book_detail_edge组件和iv_book_cover组件底部对齐，但是高度比iv_book_cover组件低8vp,不能通过设置iv_book_detail_edge组件的高度来实现。