最基本图片上传及文件上传（完整版）

不多说直接上代码

html

<input type="file" class="file" name="User_Img1" id="User_Img3" accept="image/jpeg,image/gif,image/png,image/bmp">

js

    <script src="Content/jquery-1.10.2.js"></script>
    <script>
        $(function () {
            $("#User_Img3").on("change", function () {
                var form = new FormData();
                //form.append("author", "hooyes");                        // 可以增加表单数据
                var data = $(this)[0].files[0];
                form.append("file", data);

                //var data = $(this)[0].files[0];
                //var form = new FormData(data);
                $.ajax({
                    url: '/home/Upload',
                    type: 'post',
                    //发送到服务器端的数据的格式，取消默认编码格式  
                    contentType: false,
                    dataType: 'json',
                    data: form,
                    //因为是图片，不要对其作序列化处理  
                    processData: false,
                    success: function (data) {
                        if (data) {
                            alert(data);
                        }
                    },
                    err: function (jqHXR) {
                        console.log(jqXHR.status);
                    }
                });
            });
        })
    </script>

c#MVC

public ActionResult Upload()
        {
            HttpFileCollection files = System.Web.HttpContext.Current.Request.Files;
            if (files.Count == 0) return Json("Faild", JsonRequestBehavior.AllowGet);
            MD5 md5Hasher = new MD5CryptoServiceProvider();
            /*计算指定Stream对象的哈希值*/
            byte[] arrbytHashValue = md5Hasher.ComputeHash(files[0].InputStream);
            /*由以连字符分隔的十六进制对构成的String，其中每一对表示value中对应的元素；例如“F-2C-4A”*/
            string strHashData = System.BitConverter.ToString(arrbytHashValue).Replace("-", "");
            string FileEextension = Path.GetExtension(files[0].FileName);
            string uploadDate = DateTime.Now.ToString("yyyyMMdd");
            string virtualPath = string.Format("/Upload/{0}/{1}{2}", uploadDate, strHashData, FileEextension);
            string fullFileName = Server.MapPath(virtualPath);

            //创建文件夹，保存文件
            string path = Path.GetDirectoryName(fullFileName);
            Directory.CreateDirectory(path);
            if (!System.IO.File.Exists(fullFileName))
            {
                files[0].SaveAs(fullFileName);
            }
            string fileName = files[0].FileName.Substring(files[0].FileName.LastIndexOf("\") + 1, files[0].FileName.Length - files[0].FileName.LastIndexOf("\") - 1);
            string fileSize = GetFileSize(files[0].ContentLength);
            return Json(new { FileName = fileName, FilePath = virtualPath, FileSize = fileSize }, "text/html", JsonRequestBehavior.AllowGet);
        }

 加入js图片验证：

//上传图片
        function uploadImg(self) {
            var file = self.files[0];
            if (file == undefined || file == "") {
                layer.open({
                    content: '请选择上传的图片'
                    , skin: 'msg'
                    , time: 2 //2秒后自动关闭
                });
                return;
            }
            var filename = file.name.substring(file.name.lastIndexOf('.') + 1).toLowerCase();//获取上传文件的类型
            if (filename != "jpg" && filename != "png" && filename != "jpeg") {
                layer.open({
                    content: "只能上传JPG/PNG/JPEG格式的图片,您上传的格式为：" + filename
                    , skin: 'msg'
                    , time: 2 //2秒后自动关闭
                });
                return;
            }
            if (file.size > 1024 * 1024 * 5) {
                layer.open({
                    content: '上传的图片不能超过5MB'
                    , skin: 'msg'
                    , time: 2 //2秒后自动关闭
                });
                return;
            }
            var form = new FormData();
            form.append('upfile', file);
            form.append('type', filename);
            $.ajax({
                url: '/Home/UpLoadImg',
                type: 'POST',
                data: form,
                async: true,
                cache: false,
                processData: false, // tell jQuery not to process the data
                contentType: false, // tell jQuery not to set contentType
            }).done(function (data) {
                layer.open({
                    content: data.Message
                    , skin: 'msg'
                    , time: 2 //2秒后自动关闭
                });
                if (data.ResultCode === 1000) {

                }
            }).fail(function () {
                layer.open({
                    content: '图片错误，请重新选择！'
                    , skin: 'msg'
                    , time: 2 //2秒后自动关闭
                });
            });
        }

后台：

/// <summary>
        /// 图片上传
        /// </summary>
        /// <returns></returns>
        [HttpPost]
        public ActionResult UploadImage()
        {
            //Qiniufun qiniufun = new Qiniufun();//七牛实例化
            //qiniufun.init();//七牛初始化
            var blob = Request.Form["imagefile"];
            if (blob == null)
            {
                blob = Request.Form["imagefile2"];
            }
            var type = Request.Form["type"];

            var filename = string.Format("{0:yyyyMMddHHmmssfffffff}", DateTime.Now);
            string path = HttpContext.Server.MapPath("/images/Uploads");
            string filePath = Path.Combine(path, Path.GetFileName(filename));
            //根据需要创建文件夹
            Tools.CreateFolderIfNeeded(path);

            //压缩后的文件名称
            string newFileName = string.Format("{0:yyyyMMddHHmmssfffffff}", DateTime.Now);
            try
            {
                byte[] arr = Convert.FromBase64String(blob.ToString());
                MemoryStream ms = new MemoryStream(arr);
                Bitmap bmp = new Bitmap(ms);
                if (type.ToLower() == "jpeg" || type == "jpg")
                {
                    filePath += ".jpg";
                    bmp.Save(filePath, System.Drawing.Imaging.ImageFormat.Jpeg); //保存为.jpg格式 
                    ms.Close();
                }
                else if (type.ToLower() == "png")
                {
                    filePath += ".png";
                    bmp.Save(filePath, System.Drawing.Imaging.ImageFormat.Png); //保存为.jpg格式
                    ms.Close();
                }
                else if (type.ToLower() == "gif")
                {
                    filePath += ".gif";
                    bmp.Save(filePath, System.Drawing.Imaging.ImageFormat.Gif); //保存为.jpg格式  
                    ms.Close();
                }
                QiniuUpload.UpLoadImg(filename + "." + type.ToLower(), filePath);
                var name = QiniuUpload.outlink + filename + "." + type.ToLower();//七牛地址
                //qiniufun.PutFile(qiniufun.qnSpace, qiniufun.fullname("/" + filename), filePath);//上传到七牛初
                //var name = qiniufun.outlink + qiniufun.fullname("/" + filename);//七牛地址
                return Json("Success|" + name, JsonRequestBehavior.AllowGet); //返回诸如  http://7xlcvw.com2.z0.glb.qiniucdn.com/CiviBank/201601081019336945309.jpg
            }
            catch (Exception e)
            {
                return Json("error:" + e.Message, JsonRequestBehavior.AllowGet);
            }
        }