在Windows下让不同用户使用不同的分辨率（C# 2005）

在windows下要实现不同用户拥有不同分辨率，为什么不自己动手来实现呢，看看如下实例吧：

首先制作一个能改变屏幕分辨率的C#程序，源代码如下，使用了Visual C# Express 2005 BETA 1：
1、新建Windows Application工程，取名为ScreenResolution
2、粘贴各文件的代码：
Program.cs

Using directives#region Using directives

using System;
using System.Collections.Generic;
using System.Windows.Forms;

#endregion

namespace ScreenResolution
{
    static class Program
    {
        /**//// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.EnableRTLMirroring();
            Application.Run(new Form1());
        }
    }
}

Form1.cs

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Runtime.InteropServices;

namespace ScreenResolution
{

    partial class Form1 : System.Windows.Forms.Form
    {
        public enum DMDO
        {
            DEFAULT = 0,
            D90 = 1,
            D180 = 2,
            D270 = 3
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct DEVMODE
        {
            public const int DM_DISPLAYFREQUENCY = 0x400000;
            public const int DM_PELSWIDTH = 0x80000;
            public const int DM_PELSHEIGHT = 0x100000;
            private const int CCHDEVICENAME = 32;
            private const int CCHFORMNAME = 32;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCHDEVICENAME)]
            public string dmDeviceName;
            public short dmSpecVersion;
            public short dmDriverVersion;
            public short dmSize;
            public short dmDriverExtra;
            public int dmFields;

            public int dmPositionX;
            public int dmPositionY;
            public DMDO dmDisplayOrientation;
            public int dmDisplayFixedOutput;

            public short dmColor;
            public short dmDuplex;
            public short dmYResolution;
            public short dmTTOption;
            public short dmCollate;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCHFORMNAME)]
            public string dmFormName;
            public short dmLogPixels;
            public int 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;
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        //static extern int ChangeDisplaySettings( DEVMODE lpDevMode,  int dwFlags);

        static extern int ChangeDisplaySettings([In] ref DEVMODE lpDevMode, int dwFlags);
        //private System.ComponentModel.Container components = null;
        public Form1()
        {
            InitializeComponent();
        }
//        protected override void Dispose(bool disposing)
//        {
//            if (disposing)
//            {
//                if (components != null)
//                {
//                    components.Dispose();
//                }
//            }
//            base.Dispose(disposing);
//        }

        Windows Form Designer generated code#region Windows Form Designer generated code
//        private void InitializeComponent()
//        {
//            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
//            this.ClientSize = new System.Drawing.Size(292, 273);
//            this.Text = "改变屏幕分辨率的例子";
//
//        }
        #endregion

//        static void Main()
//        {
//            Form1 r = new Form1();
//            r.ChangeRes();
//            Application.Run(new Form1());
//        }

        void ChangeRes(int chMode)
        {
            Form1 t = new Form1();
            long RetVal = 0;
            DEVMODE dm = new DEVMODE();
            dm.dmSize = (short)Marshal.SizeOf(typeof(DEVMODE));
            if (chMode == 1)
            {
                dm.dmPelsWidth = 1600;
                dm.dmPelsHeight = 1024;
                dm.dmDisplayFrequency = 85;
            }
            else if (chMode == 2)
            {
                dm.dmPelsWidth = 1024;
                dm.dmPelsHeight = 768;
                dm.dmDisplayFrequency = 85;
            }
            dm.dmFields = DEVMODE.DM_PELSWIDTH | DEVMODE.DM_PELSHEIGHT | DEVMODE.DM_DISPLAYFREQUENCY;
            RetVal = ChangeDisplaySettings(ref dm, 0);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            ChangeRes(1);
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            ChangeRes(2);
        }
    }
}

3、在Design视图下将WindowsState设置成Minimized，ShowInTaskbar设置成False

其次根据每个用户的需要修改ChangeRes方法里对分辨率的设置，生成工程后将可执行文件放在此用户的启动文件夹内

总结：
程序的原理很简单，在用户登录时将分辨率设置成用户的期望值，程序在用户登出前始终运行，但用户不会察觉，在用户登出时，程序被终止，分辨率被设置回特定值，以此实现统一登录分辨率并且各用户有自己的分辨率。

改进：
如果用户较多，可以通过程序参数来改变屏幕分辨率，避免多次生成工程并产生多个版本的混乱。

测试平台：
Windows Server 2003，Visual C# Express 2005 Beta 1