我想在MaterialApp主题中设置MediaQuery,以便在用户更改设置的情况下,FontSize会遵守用户设置。我尝试创建最终的curlScale = MediaQuery.of( context ).textScaleFactor;,并相应地在MaterialApp中设置了fontSize: 20 * curlScale,但得到的错误为"MediaQuery.of() called with a context that not context that not a MediaQuer