Issue
This Content is from Stack Overflow. Question asked by Thuận Nguyễn hữu
2 variables mediumScreen and smallScreen must required
But I wanna option.
Solution
Do this:
...
Widget? mediumScreen; //Add a question mark after the data type
This Question was asked in StackOverflow by Thuận Nguyễn hữu and Answered by Davis It is licensed under the terms of CC BY-SA 2.5. - CC BY-SA 3.0. - CC BY-SA 4.0.