文件上载控制会话从列表中删除文件后不删除

Question

我为这个问题感到沮丧了几个星期，如何为此多文件上传进行会话  if (Session["FileUpload1"] == null && FileUploadQ2.HasFile)        {            Session["FileUpload1"] = FileUploadQ2;            foreach (HttpPostedFile file in FileUploadQ2.PostedFiles)            {                listofuploadedfiles.Text += String.Format("<p><font color='black'>" + file.FileName + "</font><a class='close'><font color='red'>x</font><a>" + "</p>");            }        }        else if (Session["FileUpload1"] != null && (!FileUploadQ2.HasFile))        {            FileUploadQ2 = (FileUpload)Session["FileUpload1"];        }        else if(FileUploadQ2.HasFile)        {            Session["FileUpload1"] = FileUploadQ2;        }

Answer 1

正如@VDWWD所指出的，不应将文件存储在 Session 对象中，而应将它们存储在磁盘上。您可以在下面找到该功能的快速实现。

    public interface IFileStorage

    {

        Task UploadFile(string fileName, Stream fileContent);

        void TryRemoveFile(string fileName, out bool fileRemoved);

        void GetFile(string fileName);

    }

    public class FileSystemStorage : IFileStorage

    {

        private readonly PhysicalFileProvider _fileProvider;

        private readonly ILogger<FileSystemStorage>_logger;

        public FileSystemStorage(IFileProvider fileProvider, ILogger<FileSystemStorage> logger)

        {

            _fileProvider = (PhysicalFileProvider)fileProvider;

            _logger = logger;

        }

        public void GetFile(string fileName)

        {

            throw new NotImplementedException();

        }

        public void TryRemoveFile(string fileName, out bool fileRemoved)

        {

            try

            {

                RemoveFile(fileName);

                fileRemoved = true;

            }

            catch(Exception ex)

            {

                _logger.LogError($"Couldnt remove file {fileName}: {ex.ToString()}" );

                fileRemoved = false;

            }

        }

        public async Task UploadFile(string fileName, Stream fileContent)

        {

            var filePath = Path.Combine(_fileProvider.Root, fileName);

            if (_fileProvider.GetFileInfo(filePath).Exists)

                throw new ArgumentException("Given file already exists!");

            _logger.LogInformation($"Saving file to: {filePath}..");

            using (Stream file = File.Create(filePath))

            {

                await fileContent.CopyToAsync(file);

                file.Flush();

            }

            _logger.LogInformation($"File: {filePath} saved successfully.");

        }

    }

在 Startup.cs 中，ConfigureServices 方法添加以下行以注入 FileSystemStorage：

IFileProvider physicalProvider = new PhysicalFileProvider(Path.Combine(Directory.GetCurrentDirectory(), "AppData"));

services.AddSingleton<IFileProvider>(physicalProvider);

services.AddTransient<IFileStorage, FileSystemStorage>();

然后在控制器构造函数中获取文件系统存储实例。