Flutter Get the widget size before render

Sometimes you need to know the available width or height before you render a list of items like Images or something else, one of the best methods to do that is using the Expanded widget and the LayoutBuilder class that builds a widget tree that can depend on the parent widget’s size.
Note that you need LayouBuilder using Expanded in order to get the available width or height

    Expanded(child: LayoutBuilder(builder: (context, constraints) {
          
            var width = constraints.constrainWidth();
            var height =constraints.constrainHeight();
....... 
}));

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