to refactor a widget, in VS Code, keep the cursor on a widget (written), then press ( ctrl + . )
If you don’t like the blue wavy line suggestions in VS code:
To disable those:
// ignore_for_file: prefer_const_constructors
//ignore_for_file: sort_child_properties_last
add at the start of the dart file. If more blue wavy lines, then hover over such lines and it will show what to write to ignore the lines.

To get the child joining horizontal lines, (as like android studio).

Enable these options from settings of VS Code.