Thư Viện WinForm

 
using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential)]
public struct DEVMODE1
{
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
    public string dmDeviceName;
    public short dmSpecVersion;
    public short dmDriverVersion;
    public short dmSize;
    public short dmDriverExtra;
    public int dmFields;

    public short dmOrientation;
    public short dmPaperSize;
    public short dmPaperLength;
    public short dmPaperWidth;

    public short dmScale;
    public short dmCopies;
    public short dmDefaultSource;
    public short dmPrintQuality;
    public short dmColor;
    public short dmDuplex;
    public short dmYWindowsFormsApplication1;
    public short dmTTOption;
    public short dmCollate;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
    public string dmFormName;
    public short dmLogPixels;
    public short dmBitsPerPel;
    public int dmPelsWidth;
    public int dmPelsHeight;

    public int dmDisplayFlags;
    public int dmDisplayFrequency;

    public int dmICMMethod;
    public int dmICMIntent;
    public int dmMediaType;
    public int dmDitherType;
    public int dmReserved1;
    public int dmReserved2;

    public int dmPanningWidth;
    public int dmPanningHeight;
};



class User_32
{
    [DllImport("user32.dll")]
    public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE1 devMode);
    [DllImport("user32.dll")]
    public static extern int ChangeDisplaySettings(ref DEVMODE1 devMode, int flags);

    public const int ENUM_CURRENT_SETTINGS = -1;
    public const int CDS_UPDATEREGISTRY = 0x01;
    public const int CDS_TEST = 0x02;
    public const int DISP_CHANGE_SUCCESSFUL = 0;
    public const int DISP_CHANGE_RESTART = 1;
    public const int DISP_CHANGE_FAILED = -1;
}

 
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Drawing;

namespace SmartScreen
{
    public class Resolution
    {
        /// 

        /// Chuyển đổi độ phân giải màn hình
        /// Trả về chuỗi mô tả (Thành công hay thất bại)
        /// 
        /// Chiều rộng
        /// Chiều ngang
        /// 
        public static string SetResolution(int w, int h)
        {
            Screen screen = Screen.PrimaryScreen;

            int iWidth = w;
            int iHeight = h;


            DEVMODE1 dm = new DEVMODE1();
            dm.dmDeviceName = new String(new char[32]);
            dm.dmFormName = new String(new char[32]);
            dm.dmSize = (short)Marshal.SizeOf(dm);

            if (0 != User_32.EnumDisplaySettings(null, User_32.ENUM_CURRENT_SETTINGS, ref dm))
            {

                dm.dmPelsWidth = iWidth;
                dm.dmPelsHeight = iHeight;

                int iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_TEST);

                if (iRet == User_32.DISP_CHANGE_FAILED)
                {
                    return "Unable to process your request";
                }
                else
                {
                    iRet = User_32.ChangeDisplaySettings(ref dm, User_32.CDS_UPDATEREGISTRY);

                    switch (iRet)
                    {
                        case User_32.DISP_CHANGE_SUCCESSFUL:
                            {
                                return "Success";
                            }
                        case User_32.DISP_CHANGE_RESTART:
                            {

                                return "restart";
                            }
                        default:
                            {
                                return "Failed";
                            }
                    }
                }

            }

            return "Skip";
        }

        /// 

        /// Lấy phân giải màn hình
        /// Trả Point
        /// 
        /// 
        public static Point GetResolution()
        {
            Screen Srn = Screen.PrimaryScreen;
            Point res = new Point(Srn.Bounds.Width, Srn.Bounds.Height);
            
            return res;
        }
    }
}