As stated in the documentation, flutter prefer composition over parameters. Most of the time what you're looking for is not a property, but instead a wrapper (and sometimes a few helpers/"builder")
For borders what you want is DecoratedBox
, which has a decoration
property that defines borders ; but also background images or shadows.
Alternatively like @Aziza said, you can use Container
. Which is the combination of DecoratedBox
, SizedBox
and a few other useful widgets.