Set Margin on RecyclerView programmatically

Question

I need to set the top margin on a RecyclerView programmatically, but I get this exception:

java.lang.RuntimeException: Unable to resume activity java.lang.Cla

Answer 1

for me, the parent of recyclerview is a constraintLayout,

        val margins = (rv.layoutParams as ConstraintLayout.LayoutParams).apply {
        leftMargin = 0
        rightMargin = 0
    }
    rv.layoutParams = margins

or it will get cast error, viewGroup.LayoutParams can't be cast to COnstarintLayout.LayoutParams