CardView

public class CardView extends FrameLayout

A FrameLayout with a rounded corner background and shadow.

CardView uses elevation property on Lollipop for shadows and falls back to a custom emulated shadow implementation on older platforms.

Due to expensive nature of rounded corner clipping, on platforms before Lollipop, CardView does not clip its children that intersect with rounded corners. Instead, it adds padding to avoid such intersection (See setPreventCornerOverlap to change this behavior).

Before Lollipop, CardView adds padding to its content and draws shadows to that area. This padding amount is equal to maxCardElevation + (1 - cos45) * cornerRadius on the sides and maxCardElevation * 1.5 + (1 - cos45) * cornerRadius on top and bottom.

Since padding is used to offset content for shadows, you cannot set padding on CardView. Instead, you can use content padding attributes in XML or setContentPadding in code to set the padding between the edges of the CardView and children of CardView.

Note that, if you specify exact dimensions for the CardView, because of the shadows, its content area will be different between platforms before Lollipop and after Lollipop. By using api version specific resource values, you can avoid these changes. Alternatively, If you want CardView to add inner padding on platforms Lollipop and after as well, you can call setUseCompatPadding and pass true.

To change CardView's elevation in a backward compatible way, use setCardElevation. CardView will use elevation API on Lollipop and before Lollipop, it will change the shadow size. To avoid moving the View while shadow size is changing, shadow size is clamped by getMaxCardElevation. If you want to change elevation dynamically, you should call setMaxCardElevation when CardView is initialized.

ref androidx.cardview.R.styleable#CardView_cardBackgroundColor

ref androidx.cardview.R.styleable#CardView_cardCornerRadius

ref androidx.cardview.R.styleable#CardView_cardElevation

ref androidx.cardview.R.styleable#CardView_cardMaxElevation

ref androidx.cardview.R.styleable#CardView_cardUseCompatPadding

ref androidx.cardview.R.styleable#CardView_cardPreventCornerOverlap

ref androidx.cardview.R.styleable#CardView_contentPadding

ref androidx.cardview.R.styleable#CardView_contentPaddingLeft

ref androidx.cardview.R.styleable#CardView_contentPaddingTop

ref androidx.cardview.R.styleable#CardView_contentPaddingRight

ref androidx.cardview.R.styleable#CardView_contentPaddingBottom

Summary