PrimaryScreen.cs

using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace PrimaryScreen
{
    public class PrimaryScreen
    {
        #region Win32 API  
        [DllImport("user32.dll")]
        static extern IntPtr GetDC(IntPtr ptr);
        [DllImport("gdi32.dll")]
        static extern int GetDeviceCaps(
        IntPtr hdc, // handle to DC  
        int nIndex // index of capability  
        );
        [DllImport("user32.dll", EntryPoint = "ReleaseDC")]
        static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDc);
        #endregion
        #region DeviceCaps常量  
        const int HORZRES = 8;
        const int VERTRES = 10;
        const int LOGPIXELSX = 88;
        const int LOGPIXELSY = 90;
        const int DESKTOPVERTRES = 117;
        const int DESKTOPHORZRES = 118;
        #endregion

        #region 属性  
        /// <summary>  
        /// 获取屏幕分辨率当前物理大小  
        /// </summary>  
        public static Size WorkingArea
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                Size size = new Size();
                size.Width = GetDeviceCaps(hdc, HORZRES);
                size.Height = GetDeviceCaps(hdc, VERTRES);
                ReleaseDC(IntPtr.Zero, hdc);
                return size;
            }
        }
        /// <summary>  
        /// 当前系统DPI_X 大小 一般为96  
        /// </summary>  
        public static int DpiX
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                int DpiX = GetDeviceCaps(hdc, LOGPIXELSX);
                ReleaseDC(IntPtr.Zero, hdc);
                return DpiX;
            }
        }
        /// <summary>  
        /// 当前系统DPI_Y 大小 一般为96  
        /// </summary>  
        public static int DpiY
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                int DpiX = GetDeviceCaps(hdc, LOGPIXELSY);
                ReleaseDC(IntPtr.Zero, hdc);
                return DpiX;
            }
        }
        /// <summary>  
        /// 获取真实设置的桌面分辨率大小  
        /// </summary>  
        public static Size DESKTOP
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                Size size = new Size();
                size.Width = GetDeviceCaps(hdc, DESKTOPHORZRES);
                size.Height = GetDeviceCaps(hdc, DESKTOPVERTRES);
                ReleaseDC(IntPtr.Zero, hdc);
                return size;
            }
        }

        /// <summary>  
        /// 获取宽度缩放百分比  
        /// </summary>  
        public static float ScaleX
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                float t = (float)GetDeviceCaps(hdc, DESKTOPHORZRES);
                float d = (float)GetDeviceCaps(hdc, HORZRES);
                float ScaleX = t / d;
                ReleaseDC(IntPtr.Zero, hdc);
                return ScaleX;
            }
        }
        /// <summary>  
        /// 获取高度缩放百分比  
        /// </summary>  
        public static float ScaleY
        {
            get
            {
                IntPtr hdc = GetDC(IntPtr.Zero);
                float ScaleY = (float)(float)GetDeviceCaps(hdc, DESKTOPVERTRES) / (float)GetDeviceCaps(hdc, VERTRES);
                ReleaseDC(IntPtr.Zero, hdc);
                return ScaleY;
            }
        }
        #endregion
    }
}

//static void Main(string[] args)
//{
//    // 获取屏幕分辨率当前物理大小
//    var workingArea = PrimaryScreen.PrimaryScreen.WorkingArea;
//    Console.WriteLine($"WorkingArea: Width={workingArea.Width}, Height={workingArea.Height}");

//    // 当前系统DPI_X 大小 一般为96
//    var dpiX = PrimaryScreen.PrimaryScreen.DpiX;
//    Console.WriteLine($"DpiX: {dpiX}");

//    // 当前系统DPI_Y 大小 一般为96
//    var dpiY = PrimaryScreen.PrimaryScreen.DpiY;
//    Console.WriteLine($"DpiY: {dpiY}");

//    // 获取真实设置的桌面分辨率大小
//    var desktop = PrimaryScreen.PrimaryScreen.DESKTOP;
//    Console.WriteLine($"Desktop: Width={desktop.Width}, Height={desktop.Height}");

//    // 获取宽度缩放百分比
//    var scaleX = PrimaryScreen.PrimaryScreen.ScaleX;
//    Console.WriteLine($"ScaleX: {scaleX}");

//    // 获取高度缩放百分比
//    var scaleY = PrimaryScreen.PrimaryScreen.ScaleY;
//    Console.WriteLine($"ScaleY: {scaleY}");
//}