[RESOLVED] GetSystemMetricsForDpi alternative

[DaveDavis]

GetSystemMetrics is an old API w/o DPIAware. GetSystemMetricsForDpi does. But GetSystemMetricsForDpi is a newer API for above Windows 10 Anniversary version 1607. Is there any way to replace by a method to get the right things like VScrollbar Width? Or Is it not meanness for older than Win10 1607 because previous system is not real PerMonitorV2 at all?

gVariables.gVScrollbarWidth = NativeMethods.GetSystemMetricsForDpi(2, DeviceDpi)

gVariables.gVScrollbarWidth = NativeMethods.GetSystemMetrics(2)

<DllImport("user32", SetLastError:=True)>
Public Shared Function GetSystemMetricsForDpi(ByVal nIndex As Integer, ByVal dpi As Integer) As Integer

[.paul.]

You could use the SystemInformation Class...

SystemInformation.VerticalScrollBarWidth

[DaveDavis]

You could use the SystemInformation Class...

SystemInformation.VerticalScrollBarWidth

SystemInformation.VerticalScrollBarWidth is the same with GetSystemMetrics(2). From what I tested, it fails to get the right value in some situation (e.g. Main display is 168, 2nd is 96 Dpi). I even multiply a sgnScaleFactor, but hard to give correct sgnScaleFactor.

[DaveDavis]

GetSystemMetrics(2) always returns the main display screen data. GetSystemMetricsForDpi has 2nd parameter DeviceDpi to do computation. It is useful when the window moved to the 2nd Monitor.

[DaveDavis]

I got it:
1. While app launching, read the main screen Dpi by gInitMainScreenDpiX= NativeMethods.GetDeviceCaps(desktopDC, 88) and set VScrollbar.Width = NativeMethods.GetSystemMetrics(2)
2. While app move to another screen, VScrollbar.Width = GetSystemMetrics(2) * CurrentDeviceDpi / gInitMainScreenDpiX