aistudio-wpf-diagram/AIStudio.Wpf.DiagramDesigner/Helpers/ScreenHelper.cs

using Microsoft.Win32;
using System.Collections.Generic;
using System;
using System.Management;
using System.Runtime.InteropServices;
using System.Drawing;

namespace AIStudio.Wpf.DiagramDesigner
{
    public static class ScreenHelper
    {
        public static double ScreenScale;
        public static double MmToPixelsWidth;
        static ScreenHelper()
        {
            ScreenScale = ResetScreenScale();
            MmToPixelsWidth = MillimetersToPixelsWidth(1);
        }


        [DllImport("user32.dll", EntryPoint = "ReleaseDC")]
        public static extern IntPtr ReleaseDC(
            IntPtr hWnd,
            IntPtr hDc
            );

        [DllImport("gdi32.dll")]
        public static extern int GetDeviceCaps(
            IntPtr hdc, // handle to DC
            int nIndex // index of capability
            );

        public static System.Drawing.Size GetPhysicalDisplaySize()
        {
            Graphics g = Graphics.FromHwnd(IntPtr.Zero);
            IntPtr desktop = g.GetHdc();
            int physicalScreenHeight = GetDeviceCaps(desktop, (int)DeviceCap.Desktopvertres);
            int physicalScreenWidth = GetDeviceCaps(desktop, (int)DeviceCap.Desktophorzres);
            ReleaseDC(IntPtr.Zero, desktop);
            g.Dispose();
            return new System.Drawing.Size(physicalScreenWidth, physicalScreenHeight);
        }

        public enum DeviceCap
        {
            Desktopvertres = 117,
            Desktophorzres = 118
        }

        public static double ResetScreenScale()
        {
            using (var g = Graphics.FromHwnd(IntPtr.Zero))
            {
                IntPtr desktop = g.GetHdc();
                int physicalScreenWidth = GetDeviceCaps(desktop, (int)DeviceCap.Desktophorzres);
                return physicalScreenWidth * 1.0000 / System.Windows.SystemParameters.PrimaryScreenWidth;
            }
        }

        //public static List<string> GetMonitorPnpDeviceId()
        //{
        //    List<string> rt = new List<string>();

        //    using (ManagementClass mc = new ManagementClass("Win32_DesktopMonitor"))
        //    {
        //        using (ManagementObjectCollection moc = mc.GetInstances())
        //        {
        //            foreach (var o in moc)
        //            {
        //                var each = (ManagementObject)o;
        //                object obj = each.Properties["PNPDeviceID"].Value;
        //                if (obj == null)
        //                    continue;

        //                rt.Add(each.Properties["PNPDeviceID"].Value.ToString());
        //            }
        //        }
        //    }

        //    return rt;
        //}

        //public static byte[] GetMonitorEdid(string monitorPnpDevId)
        //{
        //    return (byte[])Registry.GetValue(@"HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\" + monitorPnpDevId + @"\Device Parameters", "EDID", new byte[] { });
        //}

        ////获取显示器物理尺寸(cm)
        //public static SizeF GetMonitorPhysicalSize(string monitorPnpDevId)
        //{
        //    byte[] edid = GetMonitorEdid(monitorPnpDevId);
        //    if (edid.Length < 23)
        //        return SizeF.Empty;

        //    return new SizeF(edid[21], edid[22]);
        //}

        //通过屏显示器理尺寸转换为显示器大小(inch)
        public static float MonitorScaler(SizeF moniPhySize)
        {
            double mDSize = Math.Sqrt(Math.Pow(moniPhySize.Width, 2) + Math.Pow(moniPhySize.Height, 2)) / 2.54d;
            return (float)Math.Round(mDSize, 1);
        }

        public static double MillimetersToPixelsWidth(double length) //length是毫米，1厘米=10毫米
        {
            //System.Windows.Forms.Panel p = new System.Windows.Forms.Panel();
            System.Drawing.Graphics g = System.Drawing.Graphics.FromHwnd(IntPtr.Zero);
            IntPtr hdc = g.GetHdc();
            int width = GetDeviceCaps(hdc, 4);     // HORZRES 
            int pixels = GetDeviceCaps(hdc, 8);     // BITSPIXEL
            g.ReleaseHdc(hdc);
            return (((double)pixels / (double)width) * (double)length);
        }

     
        
        public static double MmToWidth(double length) //length是毫米，1厘米=10毫米
        {
            return MmToPixelsWidth * length / ScreenScale;
        }

        public static double WidthToMm(double length) 
        {
            return ScreenScale * length / MmToPixelsWidth;
        }

        public static double CmToWidth(double length) //length是毫米，1厘米=10毫米
        {
            return MmToPixelsWidth * length * 10d/ ScreenScale;
        }

        public static double WidthToCm(double length)
        {
            return ScreenScale * length / (MmToPixelsWidth * 10d);
        }

        public static double InchToWidth(double length) //length是英寸，1英寸=2.54cm
        {
            return MmToPixelsWidth * length * 10d * 2.54d / ScreenScale;
        }

        public static double WidthToInch(double length) //length是英寸，1英寸=2.54cm
        {
            return ScreenScale * length / (MmToPixelsWidth * 10d * 2.54d);
        }

    }
}