Flutter：这些布局有什么区别吗？

Question

In flutter, Is there any difference between these layouts? -

• Expanded
• SizedBox.expand
• BoxConstraints.expand()

If all are same, why there are multiple layout classes/functions for same functionality?

Answer 1

As far as I know.

Expanded widget can only used inside of Row , Column and Flex . It helps to expand the children based on the flex value. By default - it's 1.

SizedBox.expand - It will expand the child as large as it's parent allows. You can put anywhere unlike Expanded.

BoxConstraints.expand - Usually takes as object of ConstrainedBox constraints property.

From the documentation -

Creates box constraints that expand to fill another box constraints.

If width or height is given, the constraints will require exactly the given value in the given dimension.