CreateProcessAsUser,C#写的windows服务弹框提示消息或者启动子进程

您好，针对您的问题，可以使用以下代码实现：

using System;
using System.Runtime.InteropServices;
using System.Security.Principal;
using System.Windows.Forms;

namespace WindowsServiceDialog
{
    public partial class ServiceDialog : Form
    {
        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern bool CreateProcessAsUser(
            IntPtr hToken,
            string lpApplicationName,
            string lpCommandLine,
            ref SECURITY_ATTRIBUTES lpProcessAttributes,
            ref SECURITY_ATTRIBUTES lpThreadAttributes,
            bool bInheritHandles,
            uint dwCreationFlags,
            IntPtr lpEnvironment,
            string lpCurrentDirectory,
            ref STARTUPINFO lpStartupInfo,
            out PROCESS_INFORMATION lpProcessInformation);

        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern bool OpenProcessToken(
            IntPtr ProcessHandle,
            uint DesiredAccess,
            out IntPtr TokenHandle);

        [DllImport("userenv.dll", SetLastError = true)]
        private static extern bool CreateEnvironmentBlock(
            out IntPtr lpEnvironment,
            IntPtr hToken,
            bool bInherit);

        [DllImport("userenv.dll", SetLastError = true)]
        private static extern bool DestroyEnvironmentBlock(
            IntPtr lpEnvironment);

        private const uint TOKEN_QUERY = 0x0008;
        private const uint TOKEN_DUPLICATE = 0x0002;
        private const uint TOKEN_ASSIGN_PRIMARY = 0x0001;
        private const uint GENERIC_ALL_ACCESS = 0x10000000;
        private const uint CREATE_NEW_CONSOLE = 0x00000010;
        private const uint CREATE_UNICODE_ENVIRONMENT = 0x00000400;
        private const int SW_SHOW = 5;

        private IntPtr _userToken;
        private IntPtr _envBlock;

        [StructLayout(LayoutKind.Sequential)]
        private struct PROCESS_INFORMATION
        {
            public IntPtr hProcess;
            public IntPtr hThread;
            public uint dwProcessId;
            public uint dwThreadId;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct SECURITY_ATTRIBUTES
        {
            public int nLength;
            public IntPtr lpSecurityDescriptor;
            public bool bInheritHandle;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct STARTUPINFO
        {
            public int cb;
            public string lpReserved;
            public string lpDesktop;
            public string lpTitle;
            public uint dwX;
            public uint dwY;
            public uint dwXSize;
            public uint dwYSize;
            public uint dwXCountChars;
            public uint dwYCountChars;
            public uint dwFillAttribute;
            public uint dwFlags;
            public short wShowWindow;
            public short cbReserved2;
            public IntPtr lpReserved2;
            public IntPtr hStdInput;
            public IntPtr hStdOutput;
            public IntPtr hStdError;
        }

        public ServiceDialog()
        {
            InitializeComponent();
        }

        private void ServiceDialog_Load(object sender, EventArgs e)
        {
            // 获取当前用户的令牌
            WindowsIdentity currentUser = WindowsIdentity.GetCurrent();
            if (currentUser != null)
            {
                if (!OpenProcessToken(currentUser.Token, TOKEN_DUPLICATE | TOKEN_ASSIGN_PRIMARY | TOKEN_QUERY, out _userToken))
                {
                    MessageBox.Show("无法获取当前用户的令牌！");
                }
            }
        }

        private void btnShowDialog_Click(object sender, EventArgs e)
        {
            MessageBox.Show("Hello World！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void btnStartProcess_Click(object sender, EventArgs e)
        {
            if (_userToken != IntPtr.Zero)
            {
                // 构造启动进程的信息结构体
                STARTUPINFO startupInfo = new STARTUPINFO();
                startupInfo.cb = Marshal.SizeOf(startupInfo);
                startupInfo.lpDesktop = "winsta0\\default";
                startupInfo.dwFlags = 0x00000100;

                // 创建进程的安全属性
                SECURITY_ATTRIBUTES processAttributes = new SECURITY_ATTRIBUTES();
                processAttributes.nLength = Marshal.SizeOf(processAttributes);
                processAttributes.bInheritHandle = true;

                // 创建线程的安全属性
                SECURITY_ATTRIBUTES threadAttributes = new SECURITY_ATTRIBUTES();
                threadAttributes.nLength = Marshal.SizeOf(threadAttributes);

                IntPtr environmentPtr = IntPtr.Zero;
                if (CreateEnvironmentBlock(out environmentPtr, _userToken, false))
                {
                    _envBlock = environmentPtr;
                }
                else
                {
                    MessageBox.Show("无法创建环境块！");
                }

                // 启动进程
                PROCESS_INFORMATION processInfo = new PROCESS_INFORMATION();
                if (!CreateProcessAsUser(
                    _userToken,
                    null,
                    "notepad.exe",
                    ref processAttributes,
                    ref threadAttributes,
                    false,
                    CREATE_NEW_CONSOLE | CREATE_UNICODE_ENVIRONMENT,
                    _envBlock,
                    null,
                    ref startupInfo,
                    out processInfo))
                {
                    MessageBox.Show("无法启动进程！");
                }

                DestroyEnvironmentBlock(_envBlock);
            }
            else
            {
                MessageBox.Show("未获取到当前用户的令牌！");
            }
        }

        private void ServiceDialog_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (_userToken != IntPtr.Zero)
            {
                CloseHandle(_userToken);
            }
        }

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool CloseHandle(IntPtr hObject);
    }
}

以上代码实现了一个 Windows 窗体程序，其中包含两个按钮，分别用于弹出提示框和启动子进程。在服务中使用时，可以将此程序安装为 Windows 服务，并在需要弹出提示框或启动子进程的时候，调用相应的方法即可。需要注意的是，如果要启动的子进程需要与当前用户交互，需要获取当前用户的令牌，并使用 `CreateProcessAsUser` 函数创建进程。