From Xojo Documentation
Indicates if the app is built with Supports HiDPI property set to ON.
result = AppSupportsHiDPI
|result||Boolean||Returns True if you are compiling or running an app with Supports HiDPI property set to ON.|
Use AppSupportsHiDPI to isolate code specific for when Supports HiDPI is ON or OFF.
DebugBuild, XojoVersion, XojoVersionString, TargetBigEndian, TargetCocoa, TargetLinux, TargetLittleEndian, TargetMachO, TargetMacOS, TargetWeb, TargetWindows, TargetX86 constants; ＃If...＃Endif statement; ConsoleApplication, ServiceApplication, WebApplication, iOSApplication classes; Application.SupportsHiDPI property.