Center

child:

Container

child:

LayoutBuilder

builder:

BuildContext

context

BoxConstraints

constraints

return

_ResizingBox

TextButton

onPressed:

()

setState

(()

_counter

++

});

},

child:

Text

'Increment Counter'

)),

Text

_counter

toString

()),

);

},

),

));

class

_ResizingBox

extends

StatefulWidget