How can I get the DPI in WPF?
10 Answers
https://docs.microsoft.com/en-us/archive/blogs/jaimer/getting-system-dpi-in-wpf-app seems to work
PresentationSource source = PresentationSource.FromVisual(this);
double dpiX, dpiY;
if (source != null) {
dpiX = 96.0 * source.CompositionTarget.TransformToDevice.M11;
dpiY = 96.0 * source.CompositionTarget.TransformToDevice.M22;
}
This is how I managed to get a "scale factor" in WPF. My laptop's resolution is 1920x1440.
int resHeight = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height; // 1440
int actualHeight = SystemParameters.PrimaryScreenHeight; // 960
double ratio = actualHeight / resHeight;
double dpi = resHeigh / actualHeight; // 1.5 which is true because my settings says my scale is 150%
Use GetDeviceCaps function:
static void Main(string[] args)
{
// 1.25 = 125%
var dpi = GetDpi();
}
[DllImport("user32.dll")]
public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("user32.dll")]
public static extern IntPtr GetDC(IntPtr hwnd);
[DllImport("gdi32.dll")]
static extern int GetDeviceCaps(IntPtr hdc, int nIndex);
private static float GetDpi()
{
IntPtr desktopWnd = IntPtr.Zero;
IntPtr dc = GetDC(desktopWnd);
var dpi = 100f;
const int LOGPIXELSX = 88;
try
{
dpi = GetDeviceCaps(dc, LOGPIXELSX);
}
finally
{
ReleaseDC(desktopWnd, dc);
}
return dpi / 96f;
}
You can try using ManagementClass:
public static string GetDPI()
{
using (ManagementClass mc = new ManagementClass("Win32_DesktopMonitor"))
{
using (ManagementObjectCollection moc = mc.GetInstances())
{
int PixelsPerXLogicalInch = 0; // dpi for x
int PixelsPerYLogicalInch = 0; // dpi for y
foreach (ManagementObject each in moc)
{
PixelsPerXLogicalInch = int.Parse((each.Properties["PixelsPerXLogicalInch"].Value.ToString()));
PixelsPerYLogicalInch = int.Parse((each.Properties["PixelsPerYLogicalInch"].Value.ToString()));
}
return PixelsPerXLogicalInch + "," + PixelsPerYLogicalInch;
}
}
}
January 25, 2017 3:54 pm
"Calling Windows 10 APIs From a Desktop Application" and
https://docs.microsoft.com/en-us/uwp/api/windows.devices.display.displaymonitor
"DisplayMonitor Class"
Namespace: Windows.Devices.Display Assemblies:Windows.Devices.Display.dll, Windows.dll
Provides information about a display monitor device connected to the system.
These data include commonly used information from the monitor's Extended Display Identification Data (EDID, which is an industry-standard display descriptor block that nearly all monitors use to provide descriptions of supported modes and general device information) and DisplayID (which is a newer industry standard that provides a superset of EDID).
RawDpiX
Gets the physical horizontal DPI of the monitor (based on the monitor’s native resolution and physical size).
RawDpiY
Gets the physical vertical DPI of the monitor (based on the monitor’s native resolution and physical size).
Basic monitor info in Windows from 2006
https://docs.microsoft.com/en-us/windows/desktop/wmicoreprov/msmonitorclass
MSMonitorClass class
WmiMonitorRawEEdidV1Block class
WmiMonitorBasicDisplayParams class
MaxHorizontalImageSize ( EDID byte 21 )
MaxVerticalImageSize ( EDID byte 22 )
( Sizes in EDID are in centimeters above and in millimeters in EDID Detailed Timing Descriptor
12 Horizontal image size, mm, 8 lsbits (0–4095 mm, 161 in)
13 Vertical image size, mm, 8 lsbits (0–4095 mm, 161 in)
14 Bits 7–4 Horizontal image size, mm, 4 msbits
Bits 3–0 Vertical image size, mm, 4 msbits
)
and
Related