C# 结合html5 批量上传文件和图片预览

来源：互联网发布：前端连接数据库编辑：程序博客网时间：2024/06/09 15:41
html5 新特性   <input id="imgsf" type="file" name="imgsf" multiple  /> input  file 中增加 multiple   属性可以选择多文件。IE9以下版本不兼容      <form id="form1" method="post" action="upload_json.ashx" enctype="multipart/form-data">    <div>     <input id="imgsf" type="file" name="imgsf" multiple  />        <input type="text" name="ceshi" value="panlitao" >        <input type="submit" value="提交" />    </div>    </form>  //预览js   <div id="imgrq">    </div>     <script type="text/javascript">                 $("#imgsf").change(function () {             var filedx = 0;             for (var i = 0, j = this.files.length; i < j; i++) {                 $("#imgrq").append("<img  src=\"" + window.URL.createObjectURL(this.files[i]) + "\" width=\"100\" height=\"100\" />");             }           });      </script> C# 代码  public class upload_json : IHttpHandler    {       // private HttpContext context;          public void ProcessRequest(HttpContext context)        {            String aspxUrl = context.Request.Path.Substring(0, context.Request.Path.LastIndexOf("/") + 1);              //文件保存目录路径            String savePath = "attached/";              //文件保存目录URL            String saveUrl = aspxUrl + "attached/";              //定义允许上传的文件扩展名            Hashtable extTable = new Hashtable();            extTable.Add("image", "gif,jpg,jpeg,png,bmp");            //extTable.Add("flash", "swf,flv");            //extTable.Add("media", "swf,flv,mp3,wav,wma,wmv,mid,avi,mpg,asf,rm,rmvb");            //extTable.Add("file", "doc,docx,xls,xlsx,ppt,htm,html,txt,zip,rar,gz,bz2");              //最大文件大小            int maxSize = 1000000;          //  this.context = context;            String newFileName = "";            for (int i = 0; i < context.Request.Files.Count;i++ )            {                HttpPostedFile imgFile = context.Request.Files[i];                                if (imgFile == null)                {                    showError("请选择文件。");                }                  String dirPath = context.Server.MapPath(savePath);                if (!Directory.Exists(dirPath))                {                    showError("上传目录不存在。");                }                  String dirName = context.Request.QueryString["dir"];                if (String.IsNullOrEmpty(dirName))                {                    dirName = "image";                }                if (!extTable.ContainsKey(dirName))                {                    showError("目录名不正确。");                }                  String fileName = imgFile.FileName;                String fileExt = Path.GetExtension(fileName).ToLower();                  if (imgFile.InputStream == null || imgFile.InputStream.Length > maxSize)                {                    showError("上传文件大小超过限制。");                }                    //修改为文件流去判断文件格式                // string exPath = mall_bll.Common.isfilltype(stream: imgFile.InputStream).ToLower();                  //  if (exPath != "jpg" && exPath != "gif" && exPath != "bmp" && exPath != "png")                //   { showError("上传文件扩展名是不允许的扩展名。\n只允许" + ((String)extTable[dirName]) + "格式。"); }                  //if (String.IsNullOrEmpty(fileExt) || Array.IndexOf(((String)extTable[dirName]).Split(','), fileExt.Substring(1).ToLower()) == -1)                //{                //    showError("上传文件扩展名是不允许的扩展名。\n只允许" + ((String)extTable[dirName]) + "格式。");                //}                  //创建文件夹                dirPath += dirName + "/";                saveUrl += dirName + "/";                if (!Directory.Exists(dirPath))                {                    Directory.CreateDirectory(dirPath);                }                String ymd = DateTime.Now.ToString("yyyyMMdd", DateTimeFormatInfo.InvariantInfo);                dirPath += ymd + "/";                saveUrl += ymd + "/";                if (!Directory.Exists(dirPath))                {                    Directory.CreateDirectory(dirPath);                }                   newFileName = DateTime.Now.ToString("yyyyMMddHHmmss_ffff", DateTimeFormatInfo.InvariantInfo) + fileExt;                String filePath = dirPath + newFileName;                  imgFile.SaveAs(filePath);            }            String fileUrl = saveUrl + newFileName;              Hashtable hash = new Hashtable();            hash["error"] = 0;            hash["url"] = fileUrl;            context.Response.AddHeader("Content-Type", "text/html; charset=UTF-8");         //   context.Response.Write(JsonMapper.ToJson(hash));            context.Response.End();        }          private void showError(string message)        {            Hashtable hash = new Hashtable();            hash["error"] = 1;            hash["message"] = message;         //   context.Response.AddHeader("Content-Type", "text/html; charset=UTF-8");         //   context.Response.Write(JsonMapper.ToJson(hash));       //     context.Response.End();        }          public bool IsReusable        {            get            {                return true;            }        }    }
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