C# 缺少的程序集引用和方法必须具有返回类型？！MVC4

我在MVC4中工作，并尝试实现jquery文件上传程序

但是在我的FileStatus类和UploadHandler中，有几个错误

-找不到命名空间FileStatus

-方法FileStatus需要一个返回类型

我有一个例子，看到方法FileStatus不返回任何东西

我不知道发生了什么事

有人能帮忙吗

FIleStatusCLASS

public class FileStatus
    {
        public const string HandlerPath = "/Upload/";

        public string group { get; set; }
        public string name { get; set; }
        public string type { get; set; }
        public int size { get; set; }
        public string progress { get; set; }
        public string url { get; set; }
        public string thumbnail_url { get; set; }
        public string delete_url { get; set; }
        public string delete_type { get; set; }
        public string error { get; set; }

        public FilesStatus() { }

        public FilesStatus(FileInfo fileInfo) { SetValues(fileInfo.Name, (int)fileInfo.Length, fileInfo.FullName); }

        public FilesStatus(string fileName, int fileLength, string fullPath) { SetValues(fileName, fileLength, fullPath); }

        private void SetValues(string fileName, int fileLength, string fullPath)
        {
            name = fileName;
            type = "image/png";
            size = fileLength;
            progress = "1.0";
            url = HandlerPath + "UploadHandler.ashx?f=" + fileName;
            delete_url = HandlerPath + "UploadHandler.ashx?f=" + fileName;
            delete_type = "DELETE";

            var ext = Path.GetExtension(fullPath);

            var fileSize = ConvertBytesToMegabytes(new FileInfo(fullPath).Length);
            if (fileSize > 3 || !IsImage(ext)) thumbnail_url = "/Content/img/generalFile.png";
            else thumbnail_url = @"data:image/png;base64," + EncodeFile(fullPath);
        }

        private bool IsImage(string ext)
        {
            return ext == ".gif" || ext == ".jpg" || ext == ".png";
        }

        private string EncodeFile(string fileName)
        {
            return Convert.ToBase64String(System.IO.File.ReadAllBytes(fileName));
        }

        static double ConvertBytesToMegabytes(long bytes)
        {
            return (bytes / 1024f) / 1024f;
        }

    }

上传处理程序

public class UploadHandler : IHttpHandler
    {
        private readonly JavaScriptSerializer js;

        private string StorageRoot
        {
            get { return Path.Combine(System.Web.HttpContext.Current.Server.MapPath("~/Files/")); } //Path should! always end with '/'
        }

        public UploadHandler()
        {
            js = new JavaScriptSerializer();
            js.MaxJsonLength = 41943040;
        }

        public bool IsReusable { get { return false; } }

        public void ProcessRequest(HttpContext context)
        {
            context.Response.AddHeader("Pragma", "no-cache");
            context.Response.AddHeader("Cache-Control", "private, no-cache");

            HandleMethod(context);
        }

        // Handle request based on method
        private void HandleMethod(HttpContext context)
        {
            switch (context.Request.HttpMethod)
            {
                case "HEAD":
                case "GET":
                    if (GivenFilename(context)) DeliverFile(context);
                    else ListCurrentFiles(context);
                    break;

                case "POST":
                case "PUT":
                    UploadFile(context);
                    break;

                case "DELETE":
                    DeleteFile(context);
                    break;

                case "OPTIONS":
                    ReturnOptions(context);
                    break;

                default:
                    context.Response.ClearHeaders();
                    context.Response.StatusCode = 405;
                    break;
            }
        }

        private static void ReturnOptions(HttpContext context)
        {
            context.Response.AddHeader("Allow", "DELETE,GET,HEAD,POST,PUT,OPTIONS");
            context.Response.StatusCode = 200;
        }

        // Delete file from the server
        private void DeleteFile(HttpContext context)
        {
            var filePath = StorageRoot + context.Request["f"];
            if (File.Exists(filePath))
            {
                File.Delete(filePath);
            }
        }

        // Upload file to the server
        private void UploadFile(HttpContext context)
        {
            var statuses = new List<FilesStatus>();
            var headers = context.Request.Headers;

            if (string.IsNullOrEmpty(headers["X-File-Name"]))
            {
                UploadWholeFile(context, statuses);
            }
            else
            {
                UploadPartialFile(headers["X-File-Name"], context, statuses);
            }

            WriteJsonIframeSafe(context, statuses);
        }

        // Upload partial file
        private void UploadPartialFile(string fileName, HttpContext context, List<FilesStatus> statuses)
        {
            if (context.Request.Files.Count != 1) throw new HttpRequestValidationException("Attempt to upload chunked file containing more than one fragment per request");
            var inputStream = context.Request.Files[0].InputStream;
            var fullName = StorageRoot + Path.GetFileName(fileName);

            using (var fs = new FileStream(fullName, FileMode.Append, FileAccess.Write))
            {
                var buffer = new byte[1024];

                var l = inputStream.Read(buffer, 0, 1024);
                while (l > 0)
                {
                    fs.Write(buffer, 0, l);
                    l = inputStream.Read(buffer, 0, 1024);
                }
                fs.Flush();
                fs.Close();
            }
            statuses.Add(new FilesStatus(new FileInfo(fullName)));
        }

        // Upload entire file
        private void UploadWholeFile(HttpContext context, List<FilesStatus> statuses)
        {
            for (int i = 0; i < context.Request.Files.Count; i++)
            {
                var file = context.Request.Files[i];

                var fullPath = StorageRoot + Path.GetFileName(file.FileName);

                file.SaveAs(fullPath);

                string fullName = Path.GetFileName(file.FileName);
                statuses.Add(new FilesStatus(fullName, file.ContentLength, fullPath));
            }
        }

        private void WriteJsonIframeSafe(HttpContext context, List<FilesStatus> statuses)
        {
            context.Response.AddHeader("Vary", "Accept");
            try
            {
                if (context.Request["HTTP_ACCEPT"].Contains("application/json"))
                    context.Response.ContentType = "application/json";
                else
                    context.Response.ContentType = "text/plain";
            }
            catch
            {
                context.Response.ContentType = "text/plain";
            }

            var jsonObj = js.Serialize(statuses.ToArray());
            context.Response.Write(jsonObj);
        }

        private static bool GivenFilename(HttpContext context)
        {
            return !string.IsNullOrEmpty(context.Request["f"]);
        }

        private void DeliverFile(HttpContext context)
        {
            var filename = context.Request["f"];
            var filePath = StorageRoot + filename;

            if (File.Exists(filePath))
            {
                context.Response.AddHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
                context.Response.ContentType = "application/octet-stream";
                context.Response.ClearContent();
                context.Response.WriteFile(filePath);
            }
            else
                context.Response.StatusCode = 404;
        }

        private void ListCurrentFiles(HttpContext context)
        {
            var files =
                new DirectoryInfo(StorageRoot)
                    .GetFiles("*", SearchOption.TopDirectoryOnly)
                    .Where(f => !f.Attributes.HasFlag(FileAttributes.Hidden))
                    .Select(f => new FilesStatus(f))
                    .ToArray();

            string jsonObj = js.Serialize(files);
            context.Response.AddHeader("Content-Disposition", "inline; filename=\"files.json\"");
            context.Response.Write(jsonObj);
            context.Response.ContentType = "application/json";
        }
    }

public类上载处理程序：IHttpHandler
{
私有只读JavaScriptSerializer js；
私有字符串存储根
{
获取{return Path.Combine（System.Web.HttpContext.Current.Server.MapPath（“~/Files/”）；}//Path应该！始终以“/”结尾
}
公共上传处理程序（）
{
js=新的JavaScriptSerializer（）；
js.MaxJsonLength=41943040；
}
公共布尔可重用{get{return false；}}
公共void ProcessRequest（HttpContext上下文）
{
AddHeader（“Pragma”，“无缓存”）；
AddHeader（“缓存控制”，“私有，无缓存”）；
HandleMethod（上下文）；
}
//基于方法处理请求
私有void HandleMethod（HttpContext上下文）
{
开关（context.Request.HttpMethod）
{
案例“头”：
案例“GET”：
if（GivenFilename（context））DeliverFile（context）；
else ListCurrentFiles（上下文）；
打破
案例“职位”：
案例“付诸表决”：
上传文件（上下文）；
打破
案例“删除”：
删除文件（上下文）；
打破
案例“选项”：
返回选项（上下文）；
打破
违约：
context.Response.ClearHeaders（）；
context.Response.StatusCode=405；
打破
}
}
私有静态void ReturnOptions（HttpContext上下文）
{
AddHeader（“允许”、“删除、获取、HEAD、POST、PUT、OPTIONS”）；
context.Response.StatusCode=200；
}
//从服务器上删除文件
私有void DeleteFile（HttpContext上下文）
{
var filePath=StorageRoot+context.Request[“f”]；
if（File.Exists（filePath））
{
File.Delete（文件路径）；
}
}
//将文件上载到服务器
私有void上载文件（HttpContext上下文）
{
变量状态=新列表（）；
var headers=context.Request.headers；
if（string.IsNullOrEmpty（头[“X-File-Name”]））
{
UploadWholeFile（上下文、状态）；
}
其他的
{
UploadPartialFile（标题[“X-File-Name”]、上下文、状态）；
}
WriteJsonIframeSafe（上下文、状态）；
}
//上载部分文件
私有void UploadPartialFile（字符串文件名、HttpContext上下文、列表状态）
{
如果（context.Request.Files.Count！=1）抛出新的HttpRequestValidationException（“尝试上载每个请求包含多个片段的分块文件”）；
var inputStream=context.Request.Files[0]。inputStream；
var fullName=StorageRoot+Path.GetFileName（文件名）；
使用（var fs=new FileStream（全名、FileMode.Append、FileAccess.Write））
{
var buffer=新字节[1024]；
var l=inputStream.Read（缓冲区，0，1024）；
而（l>0）
{
fs.写入（缓冲区，0，l）；
l=inputStream.Read（缓冲区，0，1024）；
}
fs.Flush（）；
fs.Close（）；
}
添加（新文件状态（新文件信息（全名））；
}
//上载整个文件
私有void UploadWholeFile（HttpContext上下文，列表状态）
{
for（int i=0；ipublic class FileStatus

public FilesStatus(FileInfo fileInfo)