如何用ASP.NETCore实现长尾词的文件上传与下载功能？

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本文实例分享了如何使用ASP.NET Core实现文件上传和下载的具体代码。以下为整体内容：

一、文件上传

1.1 获取文件csharppublic IActionResult UploadFile(IFormFile file){ // 保存文件 var path=Path.Combine(Directory.GetCurrentDirectory(), UploadedFiles, file.FileName); using (var stream=new FileStream(path, FileMode.Create)) { file.CopyTo(stream); } return Ok();}

二、文件下载

1.1 获取文件csharppublic IActionResult DownloadFile(string fileName){ var path=Path.Combine(Directory.GetCurrentDirectory(), UploadedFiles, fileName); if (!System.IO.File.Exists(path)) { return NotFound(); } var memory=new MemoryStream(); using (var stream=new FileStream(path, FileMode.Open)) { stream.CopyTo(memory); } memory.Position=0; return File(memory, GetContentType(path), fileName);}

private string GetContentType(string path){ var types=GetMimeTypes(); var ext=Path.GetExtension(path).ToLowerInvariant(); return types[ext];}

private Dictionary GetMimeTypes(){ return new Dictionary { {.txt, text/plain}, {.pdf, application/pdf}, {.doc, application/vnd.ms-word}, {.docx, application/vnd.openxmlformats-officedocument.wordprocessingml.document}, {.xls, application/vnd.ms-excel}, {.xlsx, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet}, {.png, image/png}, {.jpg, image/jpeg}, {.jpeg, image/jpeg}, {.gif, image/gif}, {.csv, text/csv} };}

本文实例为大家分享了ASP.NET Core实现文件上传和下载的具体代码，供大家参考，具体内容如下

一、文件上传

1.1 获取文件后缀

/// <summary> /// 获取文件后缀 /// </summary> /// <param name="fileName">文件名称</param> /// <returns></returns>         public async static Task<string> GetFileSuffixAsync(string fileName)         {             return await Task.Run(() =>             {                 string suffix = Path.GetExtension(fileName);                 return suffix;             });         }

1.2 上传单文件

public class FileMessage     {         /// <summary>         /// 原文件名称         /// </summary>         public string FileName { get; set; }         /// <summary>         /// 附件名称(协议或其他要进行数据库保存与模型绑定的命名)         /// </summary>         public string ArgumentName { get; set; }         /// <summary>         /// 文件大小(KB)         /// </summary>         public string FileSize { get; set; }         /// <summary>         /// -1：上传失败 0：等待上传 1：已上传         /// </summary>         public int FileStatus { get; set; }         /// <summary>         /// 上传结果         /// </summary>         public string UploadResult { get; set; }         /// <summary>         /// 创建实例         /// </summary>         /// <param name="fileName">原文件名称</param>         /// <param name="argumentName">(新)附件名称</param>         /// <param name="fileSize">大小</param>         /// <param name="fileStatus">文件状态</param>         /// <returns></returns>         public static FileMessage CreateNew(string fileName,             string argumentName,             string fileSize,             int fileStatus,             string uploadResult)         {             return new FileMessage()             {                 FileName = fileName,                 ArgumentName = argumentName,                 FileSize = fileSize,                 FileStatus = fileStatus,                 UploadResult = uploadResult             };         }     }

/// <summary> /// 上传文件  /// </summary>  /// <param name="file">上传的文件</param>  /// <param name="fold">要存储的文件夹</param>  /// <returns></returns>         public async static Task<FileMessage> UploadFileAsync(IFormFile file, string fold)         {             string fileName = file.FileName;             string path = Directory.GetCurrentDirectory() + @"/Upload/" + fold + "/";             if (!Directory.Exists(path))             {                 Directory.CreateDirectory(path);             }             string argumentName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + await GetFileSuffixAsync(file.FileName);             string fileSize = Math.Round((decimal)file.Length / 1024, 2) + "k";             string filePath = Path.Combine(path, argumentName);             try             {                 using (FileStream stream = new FileStream(filePath, FileMode.Create))                 {                     await file.CopyToAsync(stream);                 }                 return FileMessage.CreateNew(fileName, argumentName, fileSize, 1, "文件上传成功");             }             catch (Exception e)             {                 return FileMessage.CreateNew(fileName, argumentName, fileSize, -1, "文件上传失败：" + e.Message);             }         }

1.3 上传多文件

/// <summary> /// 上传多文件 /// </summary> /// <param name="files">上传的文件集合</param> /// <param name="fold">要存储的文件夹</param> /// <returns></returns>         public async static Task<List<FileMessage>> UploadFilesAsync(IFormFileCollection files, string fold)         {             string path = Directory.GetCurrentDirectory() + @"/Upload/" + fold + "/";             if (!Directory.Exists(path))             {                 Directory.CreateDirectory(path);             }             List<FileMessage> messages = new List<FileMessage>();             foreach (var file in files)             {                 string fileName = file.FileName;                 string argumentName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + await GetFileSuffixAsync(file.FileName);                 string fileSize = Math.Round((decimal)file.Length / 1024, 2) + "k";                 string filePath = Path.Combine(path, argumentName);                 try                 {                     using (FileStream stream = new FileStream(filePath, FileMode.Create))                     {                         await file.CopyToAsync(stream);                     }                     messages.Add(FileMessage.CreateNew(fileName, argumentName, fileSize, 1, "文件上传成功"));                 }                 catch (Exception e)                 {                     messages.Add(FileMessage.CreateNew(fileName, argumentName, fileSize, -1, "文件上传失败，失败原因：" + e.Message));                 }             }             return messages;         }

[Route("api/[controller]")]     [ApiController]     public class ManageProtocolFileController : ControllerBase     {         private readonly string createName = "";         private readonly IWebHostEnvironment _env;         private readonly ILogger<ManageProtocolFileController> _logger;         public ManageProtocolFileController(IWebHostEnvironment env,             ILogger<ManageProtocolFileController> logger)         {             _env = env;             _logger = logger;         }                  /// <summary>         /// 协议上传附件         /// </summary>         /// <param name="file"></param>         /// <returns></returns>         [HttpPost("upload")]         public async Task<FileMessage> UploadProtocolFile([FromForm] IFormFile file)         {             return await UploadFileAsync(file, "ManageProtocol");         }     }

二、文件下载

2.1 获取ContentType属性

/// <summary> /// 获取文件ContentType /// </summary> /// <param name="fileName">文件名称</param>  /// <returns></returns>         public async static Task<string> GetFileContentTypeAsync(string fileName)         {             return await Task.Run(() =>             {                 string suffix = Path.GetExtension(fileName);                 var provider = new FileExtensionContentTypeProvider();                 var contentType = provider.Mappings[suffix];                 return contentType;             });         }

2.2 执行下载

[Route("api/[controller]")] [ApiController]     public class ManageProtocolFileController : ControllerBase     {         private readonly string createName = "";         private readonly IWebHostEnvironment _env;         private readonly ILogger<ManageProtocolFileController> _logger;         public ManageProtocolFileController(IWebHostEnvironment env,             ILogger<ManageProtocolFileController> logger)         {             _env = env;             _logger = logger;         }                  /// <summary>         /// 下载附件         /// </summary>         /// <param name="fileName">文件名称</param>         /// <returns></returns>         [HttpGet("download")]         public async Task<FileStreamResult> Download([FromQuery] string fileName)         {             try             {                 string rootPath = _env.ContentRootPath + @"/Upload/ManageProtocolFile";                 string filePath = Path.Combine(rootPath, fileName);                 var stream = System.IO.File.OpenRead(filePath);                 string contentType = await GetFileContentTypeAsync(fileName);                 _logger.LogInformation("用户:" + createName + "下载后台客户协议附件:" + request.FileName);                 return File(stream, contentType, fileName);             }             catch (Exception e)             {                 _logger.LogError(e, "用户:" + createName + "下载后台客户协议附件出错，出错原因:" + e.Message);                 throw new Exception(e.ToString());             }         } }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持易盾网络。