我不明白为什么不能访问单独类中的公共函数

我试图在我的web应用程序中调用公共类内部的公共函数，但由于某种原因，该函数无法访问，即使我可以得到类fine并且该函数被标记为公共。当我调用FileUploader时，我得到的唯一选项是equals和referanceequals。我这是在做什么愚蠢的事?请不要说类是在我的应用程序中称为类的二级项目中。我没有问题访问FileUploader所在项目中的不同类。

using System;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Auth;
using Microsoft.WindowsAzure.Storage.Blob;
using Microsoft.WindowsAzure;
using System.IO;
using System.Configuration;
using FFInfo.Classes;
namespace FFInfo
{
    public partial class FUTest : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        }
        protected void btnSubmit_Click(object sender, EventArgs e)
        {
            if (fuFile.HasFile)
            {
            }
        }
    }
}

FileUploaders.cs

    using FFInfo.DAL;
using FFInfo.DAL.Tables;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;
using System;
using System.Web;
namespace FFInfo.Classes
{
    public class FileUploader
    {
        public Int64 UploadSiteImage(string ConnectionString, string ContainerName, string FilePath, HttpPostedFile UploadedFile)
        {
            CloudStorageAccount SiteImages = CloudStorageAccount.Parse(ConnectionString);
            CloudBlobClient SiteImagesBlob = SiteImages.CreateCloudBlobClient();
            CloudBlobContainer SiteImageContainer = SiteImagesBlob.GetContainerReference(ContainerName);
            SiteImageContainer.CreateIfNotExists();
            CloudBlockBlob Image = SiteImageContainer.GetBlockBlobReference(FilePath + UploadedFile.FileName);
            using (UploadedFile.InputStream)
            {
                Image.UploadFromStream(UploadedFile.InputStream);
            }
            using (var db = new Compleate())
            {
                File NewFile = new File()
                {
                    ContainerName = ContainerName,
                    FilePath = FilePath,
                    FileName = UploadedFile.FileName,
                    ContentType = UploadedFile.ContentType
                };
                db.Files.Add(NewFile);
                db.SaveChanges();
                return NewFile.FileID;
            }
        }
    }
}