Sizing elements to percentage of screen width/height

Question

Is there a simple (non-LayoutBuilder) way to size an element relative to screen size (width/height)? For example: how do I set the width of a CardView to be 65% of the scree

Answer 1

Use the LayoutBuilder Widget that will give you constraints that you can use to obtain the height that excludes the AppBar and the padding. Then use a SizedBox and provide the width and height using the constraints from the LayoutBuilder

return LayoutBuilder(builder: (context2, constraints) {
  return Column(
    children: [
      SizedBox(
        width: constraints.maxWidth,
        height: constraints.maxHeight,
        ...