CoordinatorLayout和AppBarLayout提升

我已经创建了这样的AppBar布局

它工作并在LinearLayout中投射阴影:

但是,当我把它放入CoordinatorLayout时,阴影消失了:

如何让appbar再次展示它的影子？

这实际上是一个实现细节CollapsingToolbarLayout,如源代码所示:

if (Math.abs(verticalOffset) == scrollRange) {
  // If we have some pinned children, and we're offset to only show those views,
  // we want to be elevate
  ViewCompat.setElevation(layout, layout.getTargetElevation());
} else {
  // Otherwise, we're inline with the content
  ViewCompat.setElevation(layout, 0f);
}

在CollapsingToolbarLayout显示非固定元素时删除高程- 默认情况下,只有固定子项可见时才会有高程.

原因如上，请尝试解决：

appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
            //some other code here
            ViewCompat.setElevation(appBarLayout, The Elevation In Px);
        }
    });