Example in README doesn't work in master branch

[brunoalod]

Copy & pasting the example in readme actually doesn't work.

No MediaQuery ancestor could be found starting from the context that was passed to MediaQuery.of().

[AhmedLSayed9]

I had this issue too.
In first way, You have to add this line ScreenUtil.setContext(context); and the context should be of MaterialApp Builder not MyApp class builder, just like the example.

[lizhuoyuan]

//add this line
ScreenUtil.setContext(context);