文件的上传与下载

使用MVC简单实现文件的上传与下载

　　一、使用Form表单提交上传文件

</form>　　

　　二、下载文件

　　三、创建FileContorller.cs后台控制器

　　public class FileController : Controller
　　{
　　/// <summary>
　　/// 上传文件
　　/// </summary>
　　public ActionResult Upload(HttpPostedFileBase file)
　　{
　　var fileName = file.FileName;
　　var filePath = Server.MapPath(string.Format("~/{0}", "File"));
　　file.SaveAs(Path.Combine(filePath, fileName));
　　return Json("上传成功");
　　}

　　/// <summary>
　　/// 下载文件
　　/// </summary>
　　public FileStreamResult Download(string fileName)
　　{
　　string filePath = Server.MapPath(string.Format("~/{0}/{1}", "File", fileName));
　　FileStream fs = new FileStream(filePath, FileMode.Open);
　　return File(fs, "text/plain", fileName);
　　}
　　}
使用JS实现文件的上传与下载

文件上传：

视图 view：

@{
ViewBag.Title = "Index";
}

<h2>文件管理</h2>

控制器 controller

public ActionResult Index()
        {
            return View();
        }
        /// <summary>
        /// 文件上传
        /// </summary>
        /// <returns></returns>
        [HttpPost]
        public int Upload()
        {
            //判断文件是否选中
            if (Request.Files.Count>0)
            {
                //获取文件
                var file = HttpContext.Request.Files[0];
                //获取上传文件的扩展名
                //首先将文件名按.切割
                var temp = file.FileName.Split('.');
                //获取扩展名
                var extendName = temp[temp.Length - 1];
                //获取路径
                var path = HttpContext.Server.MapPath("~/Upload/");
                //判断路径是否存在
                if (Directory.Exists(path))
                {
                    Directory.CreateDirectory(path);
                }
                //文件重新命名
                var name = DateTime.Now.ToFileTime() + "." + extendName;
                //保存上传文件
                file.SaveAs(Path.Combine(path, name));
                //返回结果
                return 1;
            }
            else
            {
                return 0;
            }
        }

文件下载：

视图 view：

控制器 contorller：

/// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public FileStreamResult Download(string fileName)
        {
            string filePath = Server.MapPath(string.Format("~/{0}/{1}", "Upload", fileName));
            FileStream fs = new FileStream(filePath, FileMode.Open);
            return File(fs, "text/plain", fileName);
        }

使用API加MVC实现图片的上传与下载

c# api+mvc实现上传和下载功能（转载）

public class FileResult
    {
        public int Code { get; set; }
        public string Msg { get; set; }
        public string Url { get; set; }
    }

//首先在api方法内新建一个控制器

//控制器内写关于上传和下载的具体代码

// 允许上传的文件扩展名
public string[] ExtentsfileName = new string[] { ".doc", ".xls", ".png",".jpg" };

public string UrlPath = "/Upload/";

//下载
        [HttpGet]
        public void DownLoad(string Url)
        {
            string filePath = HttpContext.Current.Server.MapPath(Url);
            FileInfo fi = new FileInfo(filePath);
            if (File.Exists(filePath))
            {
                HttpResponse response = HttpContext.Current.Response;
                response.Clear();
                response.ClearHeaders();
                response.ClearContent();
                response.Buffer = true;
                response.AddHeader("content-disposition", string.Format("attachment; FileName={0}", fi.Name));
                response.Charset = "GB2312";
                response.ContentEncoding = Encoding.GetEncoding("GB2312");
                response.ContentType = MimeMapping.GetMimeMapping(fi.Name);
                response.WriteFile(filePath);
                response.Flush();
                response.Close();
            }
        }

//上传
        [HttpPost]
        public FileResult UpLoad()
        {
            var request = HttpContext.Current.Request;
            if (request.Files.Count > 0)
            {
                var file = request.Files[0];
                var extenfilename = Path.GetExtension(file.FileName);

                string path = HttpContext.Current.Server.MapPath(UrlPath);
                if (!Directory.Exists(path))
                {
                    Directory.CreateDirectory(path);
                }

                if (ExtentsfileName.Contains(extenfilename.ToLower()))
                {
                    string urlfile = UrlPath + DateTime.Now.ToFileTime() + extenfilename;
                    string filepath = HttpContext.Current.Server.MapPath(urlfile);
                    file.SaveAs(filepath);
                    return new FileResult() { Code = 0, Msg = "上传成功", Url = urlfile };
                }
                else
                {
                    return new FileResult() { Code = -1, Msg = "只允许上传指定格式文件"+string.Join(",",ExtentsfileName), Url = "" };
                }
            }
            else
            {
                return new FileResult() { Code = -1, Msg = "不能上传空文件", Url = "" };
            }
        }
    }

//写完api方法之后写mvc前台

< script >
function ff()
{
var formData = new FormData();
var file = document.getElementById("f1").files[0];
formData.append("fileInfo", file);
$.ajax({
url: "https://localhost:44370/api/FileOperation/UpLoad",
type: "POST",
data: formData,
contentType: false,//必须false才会自动加上正确的Content-Type
processData: false,//必须false才会避开jQuery对 formdata 的默认处理，XMLHttpRequest会对 formdata 进行正确的处理
success: function(data) {
if (data.Code < 0)
alert(data.Msg)
else
alert(data.Url)
},
error: function(data) {
alert("上传失败！");
}
});
}

</script>