在asp.net的站点中需要调用本地EXCEL的COM组件，由于NetworkService用户的权限不够，在执行Shapes.AddPicture方法（图片大于33K左右）时会长时间无响应，需要用administrator用户来启动Excel进程才行。

上网查了一些资料，发现可以利用advapi32.dll来在asp.net应用中模拟administrator用户来启动Excel的进程，这样执行Shapes.AddPicture方法就正常了。

模拟用户的代码如下：

using System.Runtime.InteropServices;using System.Security.Principal;using System.Security.Permissions;private const int LOGON_TYPE_INTERACTIVE = 2;private const int LOGON_TYPE_PROVIDER_DEFAULT = 0;[DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]static public extern bool LogonUser(string userName, string domain, string password, int logonType, int logonProvider, ref IntPtr accessToken); public ExcelExport(string tableName){    IntPtr accessToken = IntPtr.Zero;    if (LogonUser("administrator", "domain", "password", LOGON_TYPE_INTERACTIVE, LOGON_TYPE_PROVIDER_DEFAULT, ref accessToken))    {        using (WindowsIdentity identity = new WindowsIdentity(accessToken))        {            using (WindowsImpersonationContext context = identity.Impersonate())            {                this.m_tableName = tableName;                if (ExcelRS == null)                {                    ExcelRS = new Microsoft.Office.Interop.Excel.ApplicationClass();                    ExcelRS.Visible = false;                    ExcelRS.DisplayAlerts = false;                    ExcelRS.Interactive = false;                    ExcelRS.DisplayInfoWindow = false;                }            }        }    }}