asp.net - 中等信任文件 I/O 权限

Question

根据这个MSDN article about medium trust ，在中等信任度下:

FileIOPermission is restricted. This means you can only access files in your application's virtual directory hierarchy. Your application is granted Read, Write, Append, and PathDiscovery permissions for your application's virtual directory hierarchy.

但是，对于我当前的托管服务提供商在中等信任度下运行应用程序，当我尝试在应用程序的根文件夹中读/写文件时，我得到了 access to path 'myfile.xml' denied错误。

使用以下代码读取此文件

XElement file = XElement.Load(HttpContext.Current.Server.MapPath("~/myfile.xml"));

更新完整错误:

Access to the path 'C:\WebSites\mywebsite\myfile.xml' is denied.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.UnauthorizedAccessException: Access to the path 'C:\WebSites\mywebsite\myfile.xml' is denied.

ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6 and IIS 7, and the configured application pool identity on IIS 7.5) that is used if the application is not impersonating. If the application is impersonating via , the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.

To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[UnauthorizedAccessException: Access to the path 'C:\WebSites\mywebsite\myfile.xml' is denied.]
System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) +12892935 System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath) +2481
System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy) +229 System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share) +102
System.Xml.XmlWriterSettings.CreateWriter(String outputFileName) +5224496
System.Xml.Linq.XElement.Save(String fileName, SaveOptions options) +108
mesoBoard.Services.SiteConfig.UpdateCache() +1971 mesoBoard.Web.MvcApplication.OnApplicationStarted() +62 Ninject.Web.Mvc.NinjectHttpApplication.Application_Start() +604

[HttpException (0x80004005): Access to the path 'C:\WebSites\mywebsite\myfile.xml' is denied.]
System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +3985477 System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +191
System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +325 System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +407 System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +375

[HttpException (0x80004005): Access to the path 'C:\WebSites\mywebsite\myfile.xml' is denied.]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +11524352
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +141
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +4782309

Answer 1

您需要确保运行网站的应用程序池的用户帐户对文件/文件夹具有读/写权限。默认情况下，我认为您应该具有读取权限但没有写入权限。此外，出于安全原因，最好将该文件从 wwwroot 文件夹中移到不会损坏整个应用程序的位置。

webdir/data
webdir/data/myfile.xml

webdir/wwwroot
webdir/wwwroot/default.aspx