从列表中删除文件后，文件上传控制会话不会删除 [英] File Upload Control Session does not remove after remove file from list

问题描述

这个问题让我沮丧了几个星期

I had frustrated for a few week for this issue,

如何为多文件上传进行会话

How can I do session for this Multiple File Upload

  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;
        }

推荐答案

正如@VDWWD所指出的那样，您不应将文件存储在Session对象中，而应将其存储在磁盘上.您可以在下面找到该功能的快速实现.

As @VDWWD pointed out, you should not store files in the Session object - store them on disk instead. Below you can find fast implementation of that feature.

    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:

In Startup.cs, ConfigureServices method add below lines to inject 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FileSystemStorage实例.

Then in your controller constructor obtain the FileSystemStorage instance.

这篇关于从列表中删除文件后，文件上传控制会话不会删除的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！