小编Tha*_*nIT的帖子

为什么此代码返回“不支持指定的方法”。

using System;
using System.IO;
using System.Security.Cryptography;
using System.Web.Mvc;

public class ETagAttribute : ActionFilterAttribute
{
    private string GetToken(Stream stream) {
        MD5 md5 = MD5.Create();
        byte [] checksum = md5.ComputeHash(stream);
        return Convert.ToBase64String(checksum, 0, checksum.Length);
    }

    public override void OnResultExecuted(ResultExecutedContext filterContext)
    {
        filterContext.HttpContext.Response.AppendHeader("ETag", GetToken(filterContext.HttpContext.Response.OutputStream));
        base.OnResultExecuted(filterContext);
    }
}

这应该有效，但不是。

显然微软覆盖了 System.Web.HttpResponseStream.Read(Byte[] buffer, Int32 offset, Int32 count) 以便它返回“不支持指定的方法。”，不知道为什么他们会这样做，因为它继承了系统。 IO.Stream 基类...

堆栈跟踪：

[NotSupportedException: Specified method is not supported.]
   System.Web.HttpResponseStream.Read(Byte[] buffer, Int32 offset, Int32 count) +29
   ETagAttribute.ReadFully(Stream input) in Filters\ETagAttribute.cs:11
   ETagAttribute.GetToken(Stream stream) in Filters\ETagAttribute.cs:22
   ETagAttribute.OnResultExecuted(ResultExecutedContext …

我有一个问题,如果你请帮助我,我有一个错误

必须声明标量变量"@Deitails".

我不知道这个问题是什么,因为我不知道Scalar是什么

 var sqlCon = new
 SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);

             // GET CONFERENCE ROLE ID


             SqlCommand cmd = new SqlCommand();
             cmd.Connection = sqlCon;
             cmd.CommandText = "select Conference_Role_ID from AuthorPaper
 where Paper_ID = @PaperId";
             cmd.Parameters.AddWithValue("@PaperId",
 paperId);
             cmd.Connection.Open();
             string ConferenceRoleId = cmd.ExecuteScalar().ToString();
             cmd.Connection.Close();
             cmd.Dispose();




                 string query2 = @"insert into
 ReviewPaper(Overall_Rating,Paper_id,Conference_role_id,Deitails)

                              values(0,@paperId,@ConferenceRoleId,@Deitails);select
 SCOPE_IDENTITY() as RPID";

                 cmd = new SqlCommand(query2, sqlCon);
                 cmd.Parameters.AddWithValue("@paperId",
 paperId);
                 cmd.Parameters.AddWithValue("@ConferenceRoleId",
 ConferenceRoleId);

             string ReviewPaperId;

                 try
                 {
                     cmd.Connection.Open();
                     ReviewPaperId = cmd.ExecuteScalar().ToString();
                     cmd.Connection.Close();
                 }
                 catch (Exception ee) { throw ee; }
                 finally { cmd.Dispose(); } …