Não consegui entender muito a diferença entre o exemplo 9 e o exemplo 10.
Example 9 # Example 9 layout ConstrainedBox( constraints: const BoxConstraints( minWidth: 70, minHeight: 70, maxWidth: 150, maxHeight: 150, ), child: Container(color: red, width: 10, height: 10), ) content_copy You might guess that the Container has to be between 70 and 150 pixels, but you would be wrong. The ConstrainedBox only imposes additional constraints from those it receives from its parent.
Here, the screen forces the ConstrainedBox to be exactly the same size as the screen, so it tells its child Container to also assume the size of the screen, thus ignoring its constraints parameter.
Example 10 # Example 10 layout Center( child: ConstrainedBox( constraints: const BoxConstraints( minWidth: 70, minHeight: 70, maxWidth: 150, maxHeight: 150, ), child: Container(color: red, width: 10, height: 10), ), ) content_copy Now, Center allows ConstrainedBox to be any size up to the screen size. The ConstrainedBox imposes additional constraints from its constraints parameter onto its child.
The Container must be between 70 and 150 pixels. It wants to have 10 pixels, so it ends up having 70 (the minimum).
