C# Scaling UserControl content to match users Dpi/Font Size


How do I get my OwnerDrawn UserControl to respect the users dpi (96/120/xxx) and/or font-size (normal, large, extra large)?

Some people suggest to use the DpiX and DpiY properties on a Graphics object, but that doesn't seem to to anything in my control (i.e. they are always set to 96, regardless of which font-size or dpi I choose).

There is another similar question here on StackOverflow where it suggests to use the AutoScale properties, but the suggested solutions don't really do anything either.

Is there no way of doing this in .NET except for relying on WPF?

Best Answer

You would need to set the AutoScaleMode property of the UserControl to AutoScaleMode.Dpi, and not set the AutoScale property to true. If you do, it will reset the AutoScaleMode back to None. The AutoScale property is obsolete and is there only for backwards compatibility (see the Important Note in this MSDN article).

Also, in Windows Vista/7, unless you explicitly specify that your application is DPI-aware, Windows will emulate a default DPI environment so that your application renders with 96 DPI, then scale the resulting bitmap to the appropriate size. To avoid that, you can alter your application manifest to inform Windows that you are in fact DPI aware - see the Using manifest to declare DPI awareness section in this article.