基于ajax实现上传图片代码示例解析

js源码:

///  
///  
 
/*! 
 * jQuery upload 
 * 用于上传单个文件,上传成功后,返回文件路径。 
 * 本插件依赖jQuery,jquery.form 请在使用时引入依赖的文件 
 * 
 * Date: 2014/4/23 
 */ 
/* 
使用: 
html: 
js: $(document).ready(function () { //$(".upload").upload({ // uploadData: { id: "12233" }, // successFn: function (response, statusText, xhr, $this) { // alert(response.Data.RelativePath) // }, // deleteData: { id: function () { return "asdfasdf" } } //}); $(".upload").upload({ uploadData: { id: "12233" }, successFn: "success", //可以是字符串 deleteData: { id: function () { return "asdfasdf" } } }); }); //上传成功后执行该函数 function success(response, statusText, xhr, $this) { //比如插入编辑器 alert(response.Data.RelativePath + $this.attr("value")) } */ (function ($) { $.extend($.fn, { upload: function (settings) { var options = $.extend({ fileType: "gif|jpg|jpeg|png|bmp", //允许的文件格式 uploadUrl: "/ajax/handler.ashx?action=uploadfile", //上传URL地址 deleteUrl: "/ajax/handler.ashx?action=deletefile", //删除URL地址 width: "", //图片显示的宽度 height: 100, //图片显示的高度 imgSelector: ".imgdiv", //图片选择器 uploadData: {}, //上传时需要附加的参数 deleteData: {}, //删除时需要附加的参数 deleteFn: function ($parent, showMessage) { //删除图片的方法(默认方法使用POST提交) methods.deleteImage($parent, showMessage); }, beforeSubmitFn: "beforeUpload", //上传前执行的方法 原型 beforeSubmit(arr, $form, options); successFn: "uploadSuccess", //上传成功后执行的方法 uploadSuccess(response, statusText, xhr, $this) errorFn: "uploadError" //上传失败后执行的方法 }, settings); //上传准备函数 var methods = { //验证文件格式 checkFile: function (filename) { var pos = filename.lastIndexOf("."); var str = filename.substring(pos, filename.length); var str1 = str.toLowerCase(); if (typeof options.fileType !== 'string') { options.fileType = "gif|jpg|jpeg|png|bmp"; } var re = new RegExp("\.(" + options.fileType + ")$"); return re.test(str1); }, //创建表单 createForm: function () { var $form = document.createElement("form"); $form.action = options.uploadUrl; $form.method = "post"; $form.enctype = "multipart/form-data"; $form.style.display = "none"; //将表单加当document上, document.body.appendChild($form); //创建表单后一定要加上这句否则得到的form不能上传。document后要加上body,否则火狐下不行。 return $($form); }, //创建图片 createImage: function () { //不能用 new Image() 来创建图片,否则ie下不能改变img 的宽高 var img = $(document.createElement("img")); img.attr({ "title": "双击图片可删除图片!" }); if (options.width !== "") { img.attr({ "width": options.width }); } if (options.height !== "") { img.attr({ "height": options.height }); } return img; }, showImage: function (filePath, $parent) { var $img = methods.createImage(); $parent.find(options.imgSelector).find("img").remove(); //要先append再给img赋值,否则在ie下不能缩小宽度。 $img.appendTo($parent.find(options.imgSelector)); $img.attr("src", filePath); this.bindDelete($parent); }, bindDelete: function ($parent) { $parent.find(options.imgSelector).find("img").bind("dblclick", function () { options.deleteFn($parent, true); }); }, deleteImage: function ($parent, showMessage) { var $fileInput = $parent.find("input:hidden"); if ($fileInput.val() !== "") { var data = $.extend(options.deleteData, { filePath: $fileInput.val(), t: Math.random() }); $.post(options.deleteUrl, data, function (response) { if (showMessage) { alert(response.MessageContent) } if (response.MessageType == 1) { $fileInput.val(""); $parent.find(options.imgSelector).find("img").remove(); } }, "JSON"); } }, onload: function ($parent) { var hiddenInput = $parent.find("input:hidden"); if (typeof hiddenInput !== "undefined" && hiddenInput.val() !== "") { var img = methods.createImage(); if ($parent.find(options.imgSelector).find("img").length > 0) { $parent.find(options.imgSelector).find("img").remove(); } //要先append再给img赋值,否则在ie下不能缩小宽度。 img.appendTo($parent.find(options.imgSelector)); img.attr("src", hiddenInput.val()); methods.bindDelete($parent); } } }; //上传主函数 this.each(function () { var $this = $(this); methods.onload($this.parent()); $this.bind("click", function () { var $fileInput = $(this).parent().find("input:file"); var fileBox = $fileInput.parent(); if ($fileInput.val() === "") { alert("请选择要上传的图片!"); return false; } //验证图片 if (!methods.checkFile($fileInput.val())) { alert("文件格式不正确,只能上传格式为:" + options.fileType + "的文件。"); return false; } //若隐藏域中有图片,先删除图片 if ($fileInput.val() !== "") { options.deleteFn($this.parent(), false); //methods.deleteImage($this.parent(), false); } //创建表单 var $form = methods.createForm(); //把上传控件附加到表单 $fileInput.appendTo($form); fileBox.html(" 正在上传... "); $this.attr("disabled", true); //构建ajaxSubmit参数 var data = {}; data.data = options.uploadData; data.type = "POST"; data.dataType = "JSON"; //上传前 data.beforeSubmit = function (arr, $form, options) { var beforeSubmitFn; try { beforeSubmitFn = eval(options.beforeSubmitFn) } catch (err) { }; if (beforeSubmitFn) { var $result = beforeSubmitFn(arr, $form, options); if (typeof ($result) == "boolean") return $result; } }; //上传失败 data.error = function (response, statusText, xhr, $form) { var errorFn; try { errorFn = eval(options.errorFn) } catch (err) { }; if (errorFn) { errorFn(response.responseText, statusText, xhr, $this); } }; //上传成功 data.success = function (response, statusText, xhr, $form) { //response = eval("(" + response + ")"); if (response.MessageType == 1) { methods.showImage(response.Data.RelativePath, $this.parent()); $this.parent().find("input:hidden").val(response.Data.RelativePath); var successFn; try { successFn = eval(options.successFn) } catch (err) { }; if (successFn) { $.ajaxSetup({ cache: false });//这个不能少,否则ie下会提示下载 successFn(response, statusText, xhr, $this); } } else { alert(response.MessageContent); } $this.attr("disabled", false); fileBox.html(""); $form.remove(); }; try { //开始ajax提交表单 $form.ajaxSubmit(data); } catch (e) { alert(e.message); } }); }); } }); })(jQuery)

html代码:

 
 
 
 
 
 
 
 
 
 
 

服务器端使用一般处理程序:

public void ProcessRequest(HttpContext context) 
{ 
  context.Response.ContentType = "application/json"; 
  var action = context.Request.QueryString.Get("action").ToLower(); 
  var response = new JsonResult(StatusMessageType.Error, "没有权限或无效请求。").ToJson(); 
  switch (action) 
  { 
 
    case "uploadfile": 
      if (context.Request.Files.Count > 0) 
        response = UploadFile(context.Request); 
      break; 
    case "deletefile": 
      response = DeleteFile(context.Request.Form); 
      break; 
    default: 
      break; 
  } 
  context.Response.Write(response); 
} 
///  
///  
///  
///  
///  
private string UploadFile(HttpRequest request) 
{ 
  if (request.Files.Count == 0) 
    return new JsonResult(StatusMessageType.Error, "没有可处理的数据。").ToJson(); 
  var id = request.Form.Get("id", ""); 
 
  var file = request.Files[0]; 
  if (file == null || file.ContentLength <= 0 || string.IsNullOrEmpty(file.FileName)) 
    return new JsonResult(StatusMessageType.Error, "没有可处理的数据。").ToJson(); 
 
  //IStoreFile storeFile = null; 
 
  string[] datePaths = new string[] { "~/uploads/" }; 
  datePaths = datePaths.Union(DateTime.Now.ToString("yyyy-MM-dd").Split('-')).ToArray(); 
  var relativePath = storeProvider.JoinDirectory(datePaths); 
 
  var dirPath = HttpContext.Current.Server.MapPath(relativePath); 
 
  if (!System.IO.Directory.Exists(dirPath)) 
    System.IO.Directory.CreateDirectory(dirPath); 
 
  var fileName = GenerateFileName(Path.GetExtension(file.FileName)); 
 
  var filePath = Path.Combine(dirPath, fileName); 
  file.SaveAs(filePath); 
  return new JsonResult(StatusMessageType.Success, "上传成功。", new 
  { 
    RelativePath = WebUtility.ResolveUrl(Path.Combine(relativePath, fileName)), 
    Size = file.ContentLength, 
    Id = id, 
  }).ToJson(); 
} 
 
public string DeleteFile(NameValueCollection form) 
{ 
  var filePath = form.Get("filePath", "").Trim(); 
  if (string.IsNullOrEmpty(filePath)) 
    return new JsonResult(StatusMessageType.Error, "无效提交。").ToJson(); 
 
  try 
  { 
    if (System.IO.File.Exists(HttpContext.Current.Server.MapPath(filePath))) 
    { 
      System.IO.File.Delete(HttpContext.Current.Server.MapPath(filePath)); 
      return new JsonResult(StatusMessageType.Success, "文件删除成功。").ToJson(); 
    } 
    else 
    { 
      return new JsonResult(StatusMessageType.Success, "找不到该文件。").ToJson(); 
    } 
  } 
  catch (Exception) 
  { 
    return new JsonResult(StatusMessageType.Hint, "发生错误。").ToJson(); 
  } 
} 
 
///  
/// 生成随机文件名 
///  
///  
private string GenerateFileName(string extension) 
{ 
  return DateTime.Now.Ticks.ToString() + extension; 
} 

程序使用的是framework4.0,所以使用了一些扩展方法。

JsonTesult类代码:

[Serializable] 
public class JsonResult 
{ 
  private StatusMessageType _messageType; 
  private string _messageContent; 
 
 
  ///  
  ///  
  ///  
  ///  
  ///  
  ///  
  public JsonResult(StatusMessageType messageType, string messageContent, object data = null) 
  { 
    _messageType = messageType; 
    _messageContent = messageContent; 
    Data = data; 
  } 
 
  public StatusMessageType MessageType 
  { 
    get { return _messageType; } 
    set { _messageType = value; } 
  } 
 
  public string MessageContent 
  { 
    get { return _messageContent; } 
    set { _messageContent = value; } 
  } 
 
  public object Data { get; set; } 
 
  public string ToJson() 
  { 
    JavaScriptSerializer serializer = new JavaScriptSerializer(); 
    var json = serializer.Serialize(this); 
 
    //string p = @"\\/Date(\d+)\\/"; 
    //MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString); 
    //Regex reg = new Regex(p); 
    //json = reg.Replace(json, matchEvaluator); 
    return json; 
  } 
 
  private static string ConvertJsonDateToDateString(Match m) 
  { 
    string result = string.Empty; 
    DateTime dt = new DateTime(1970, 1, 1); 
    dt = dt.AddMilliseconds(long.Parse(m.Groups[1].Value)); 
    dt = dt.ToLocalTime(); 
    result = dt.ToString("d"); 
    return result; 
  } 
} 

StatusMessageType枚举类:

///  
/// 提示消息类别 
///  
public enum StatusMessageType 
{ 
  ///  
  /// 权限不足 
  ///  
  NoAccess = -2, 
  ///  
  /// 错误 
  ///  
  Error = -1, 
  ///  
  /// 成功 
  ///  
  Success = 1, 
 
  ///  
  /// 提示信息 
  ///  
  Hint = 0 
} 

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脚本之家。

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