Intellij idea deprecated no strikeout/strikethrough

IntelliJ had a bug in 2018.3, 2018.2.2 (182.4129.33). It was fixed in builds 191.65, 183.3691.

Setting -Dide.text.effect.new.metrics=false in the .vmoptions fixes the problem.

In addition to Ionghua's answer .....

If you find that IntelliJ is still not striking out deprecated methods, even though you have enabled the inspection as above, check to make sure that your code is not ignoring deprecation warnings with @SuppressWarnings("deprecation").

Open Settings -> Type Inspections to go to inspection settings -> Type Deprecated to find out all deprecated related inspection settings -> Check Deprecated API usage.

In addition to longhua's answer... and vegemite4me...

Another possible source for this problem might be custom color themes.

If you are using a custom theme, make sure that it contains strikethrough. I was using monokai-sublime and there is no strikethrough for @Deprecated annotations. When I changed the color theme from monokai to darcula strikethrough worked as expected.