基於ajax實現上傳圖片程式碼示例解析

阿新 • • 發佈：2020-12-03

js原始碼：

/// <reference path="jquery-1.8.3.js" /> 
/// <reference path="ajaxForm/jquery.form.js" /> 
 
/*! 
 * jQuery upload 
 * 用於上傳單個檔案，上傳成功後,返回檔案路徑。 
 * 本外掛依賴jQuery，jquery.form 請在使用時引入依賴的檔案 
 * 
 * Date: 2014/4/23 
 */ 
/* 
使用: 
html: 
<div style="width: 100%; float: left;"> 
  <input type="hidden" id="hfThumbnail" value="/uploads/2014/04/23/635338686611432716.jpg" /> 
  <div class="imgdiv"></div> 
  <span class="img_span"> 
    <input type="file" name="file" /> 
  </span> 
   
  <input type="button" value="上傳" class="upload" /> 
</div> 
<div style="width: 100%; float: left;"> 
  <input type="hidden" id="hfThumbnail" value="/uploads/2014/04/23/635338686611432716.jpg" /> 
  <div class="imgdiv"></div> 
  <span class="img_span"> 
    <input type="file" name="file" /> 
  </span> 
   
  <input type="button" value="上傳" class="upload" /> 
</div> 
 
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",//可以是字串 
    deleteData: { id: function () { return "asdfasdf" } } 
  }); 
}); 
 
//上傳成功後執行該函式 
function success(response,$this) { 
  //比如插入編輯器 
  alert(response.Data.RelativePath + $this.attr("value")) 
} 
*/ 
 
(function ($) { 
  $.extend($.fn,{ 
    upload: function (settings) { 
 
      var options = $.extend({ 
        fileType: "gif|jpg|jpeg|png|bmp",//允許的檔案格式 
        uploadUrl: "/ajax/handler.ashx?action=uploadfile",//上傳URL地址 
        deleteUrl: "/ajax/handler.ashx?action=deletefile",//刪除URL地址 
        width: "",//圖片顯示的寬度 
        height: 100,//圖片顯示的高度 
        imgSelector: ".imgdiv",//圖片選擇器 
        uploadData: {},//上傳時需要附加的引數 
        deleteData: {},//刪除時需要附加的引數 
        deleteFn: function ($parent,showMessage) {       //刪除圖片的方法(預設方法使用POST提交) 
          methods.deleteImage($parent,showMessage); 
        },beforeSubmitFn: "beforeUpload",//上傳前執行的方法 原型 beforeSubmit(arr,$form,options); 
        successFn: "uploadSuccess",//上傳成功後執行的方法 uploadSuccess(response,$this) 
        errorFn: "uploadError"                 //上傳失敗後執行的方法 
      },settings); 
 
      //上傳準備函式 
      var methods = { 
        //驗證檔案格式 
        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); 
        },//建立表單 
        createForm: function () { 
          var $form = document.createElement("form"); 
          $form.action = options.uploadUrl; 
          $form.method = "post"; 
          $form.enctype = "multipart/form-data"; 
          $form.style.display = "none"; 
          //將表單加當document上， 
          document.body.appendChild($form); //建立表單後一定要加上這句否則得到的form不能上傳。document後要加上body,否則火狐下不行。 
          return $($form); 
        },//建立圖片 
        createImage: function () { 
          //不能用 new Image() 來建立圖片，否則ie下不能改變img 的寬高 
          var img = $(document.createElement("img")); 
          img.attr({ "title": "雙擊圖片可刪除圖片！" }); 
          if (options.width !== "") { 
            img.attr({ "width": options.width }); 
          } 
          if (options.height !== "") { 
            img.attr({ "height": options.height }); 
          } 
          return img; 
        },showImage: function (filePath,$parent) { 
          var $img = methods.createImage(); 
          $parent.find(options.imgSelector).find("img").remove(); 
          //要先append再給img賦值，否則在ie下不能縮小寬度。 
          $img.appendTo($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) { $parent.find(options.imgSelector).find("img").remove(); } 
            //要先append再給img賦值，否則在ie下不能縮小寬度。  
            img.appendTo($parent.find(options.imgSelector)); 
            img.attr("src",hiddenInput.val()); 
            methods.bindDelete($parent); 
          } 
        } 
      }; 
      //上傳主函式 
      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 ($fileInput.val() === "") { 
            alert("請選擇要上傳的圖片！"); 
            return false; 
          } 
          //驗證圖片 
          if (!methods.checkFile($fileInput.val())) { 
            alert("檔案格式不正確，只能上傳格式為：" + options.fileType + "的檔案。"); 
            return false; 
          } 
          //若隱藏域中有圖片，先刪除圖片 
          if ($fileInput.val() !== "") { 
            options.deleteFn($this.parent(),false); 
            //methods.deleteImage($this.parent(),false); 
          } 
 
          //建立表單 
          var $form = methods.createForm(); 
 
          //把上傳控制元件附加到表單 
          $fileInput.appendTo($form); 
          fileBox.html("<img src=\"/admin/styles/images/loading.gif\" />  正在上傳... "); 
          $this.attr("disabled",true); 
 
          //構建ajaxSubmit引數 
          var data = {}; 
          data.data = options.uploadData; 
          data.type = "POST"; 
          data.dataType = "JSON"; 
          //上傳前 
          data.beforeSubmit = function (arr,options) { 
 
            var beforeSubmitFn; 
            try { beforeSubmitFn = eval(options.beforeSubmitFn) } catch (err) { }; 
            if (beforeSubmitFn) { 
              var $result = beforeSubmitFn(arr,options); 
              if (typeof ($result) == "boolean") 
                return $result; 
            } 
          }; 
          //上傳失敗 
          data.error = function (response,$form) { 
            var errorFn; 
            try { errorFn = eval(options.errorFn) } catch (err) { }; 
            if (errorFn) { 
              errorFn(response.responseText,$this); 
            } 
          }; 
          //上傳成功 
          data.success = function (response,$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) { 
                $.ajaxSetup({ cache: false });//這個不能少，否則ie下會提示下載 
                successFn(response,$this); 
              } 
 
 
            } else { 
              alert(response.MessageContent); 
            } 
            $this.attr("disabled",false); 
            fileBox.html("<input type=\"file\" name=\"file\" />"); 
            $form.remove(); 
          }; 
 
          try { 
            //開始ajax提交表單 
            $form.ajaxSubmit(data); 
          } catch (e) { 
            alert(e.message); 
          } 
        }); 
      }); 
    } 
  }); 
})(jQuery)

html程式碼：

<!DOCTYPE html> 
 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head runat="server"> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<script src="Scripts/jquery/jquery-1.8.3.js"></script> 
<script src="Scripts/jquery/ajaxForm/jquery.form.js"></script> 
<script src="Scripts/jquery/jquery.upload.js"></script> 
<title></title> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div style="width: 100%; float: left;"> 
  <input type="hidden" id="hfThumbnail" value="/uploads/2014/04/23/635338686611432716.jpg" /> 
  <div class="imgdiv"></div> 
  <span class="img_span"> 
    <input type="file" name="file" /> 
  </span> 
    
  <input type="button" value="上傳" class="upload" /> 
</div> 
<div style="width: 100%; float: left;"> 
  <input type="hidden" id="hfThumbnail" value="/uploads/2014/04/23/635338686611432716.jpg" /> 
  <div class="imgdiv"></div> 
  <span class="img_span"> 
    <input type="file" name="file" /> 
  </span> 
    
  <input type="button" value="上傳" class="upload" /> 
</div> 
</form> 
<script type="text/javascript"> 
  $(document).ready(function () { 
    //$(".upload").upload({ 
    //  uploadData: { id: "12233" },$this) { 
    //    alert(response.Data.RelativePath) 
    //  },//  deleteData: { id: function () { return "asdfasdf" } } 
    //}); 
    $(".upload").upload({ 
      uploadData: { id: "12233" },deleteData: { id: function () { return "asdfasdf" } } 
    }); 
  }); 
 
  //上傳成功後執行該函式 
  function success(response,$this) { 
    //比如插入編輯器 
    alert(response.Data.RelativePath + $this.attr("value")) 
  } 
</script> 
</body> 
</html>

伺服器端使用一般處理程式：

public void ProcessRequest(HttpContext context) 
{ 
  context.Response.ContentType = "application/json"; 
  var action = context.Request.QueryString.Get<string>("action").ToLower(); 
  var response = new JsonResult(StatusMessageType.Error,"沒有許可權或無效請求。").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); 
} 
/// <summary> 
///  
/// </summary> 
/// <param name="file"></param> 
/// <returns></returns> 
private string UploadFile(HttpRequest request) 
{ 
  if (request.Files.Count == 0) 
    return new JsonResult(StatusMessageType.Error,"沒有可處理的資料。").ToJson(); 
  var id = request.Form.Get<string>("id",""); 
 
  var file = request.Files[0]; 
  if (file == null || file.ContentLength <= 0 || string.IsNullOrEmpty(file.FileName)) 
    return new JsonResult(StatusMessageType.Error,"沒有可處理的資料。").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,"上傳成功。",new 
  { 
    RelativePath = WebUtility.ResolveUrl(Path.Combine(relativePath,fileName)),Size = file.ContentLength,Id = id,}).ToJson(); 
} 
 
public string DeleteFile(NameValueCollection form) 
{ 
  var filePath = form.Get<string>("filePath","").Trim(); 
  if (string.IsNullOrEmpty(filePath)) 
    return new JsonResult(StatusMessageType.Error,"無效提交。").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,"檔案刪除成功。").ToJson(); 
    } 
    else 
    { 
      return new JsonResult(StatusMessageType.Success,"找不到該檔案。").ToJson(); 
    } 
  } 
  catch (Exception) 
  { 
    return new JsonResult(StatusMessageType.Hint,"發生錯誤。").ToJson(); 
  } 
} 
 
/// <summary> 
/// 生成隨機檔名 
/// </summary> 
/// <returns></returns> 
private string GenerateFileName(string extension) 
{ 
  return DateTime.Now.Ticks.ToString() + extension; 
}

程式使用的是framework4.0，所以使用了一些擴充套件方法。

JsonTesult類程式碼：

[Serializable] 
public class JsonResult 
{ 
  private StatusMessageType _messageType; 
  private string _messageContent; 
 
 
  /// <summary> 
  ///  
  /// </summary> 
  /// <param name="messageType"></param> 
  /// <param name="messageContent"></param> 
  /// <param name="data"></param> 
  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列舉類：

/// <summary> 
/// 提示訊息類別 
/// </summary> 
public enum StatusMessageType 
{ 
  /// <summary> 
  /// 許可權不足 
  /// </summary> 
  NoAccess = -2,/// <summary> 
  /// 錯誤 
  /// </summary> 
  Error = -1,/// <summary> 
  /// 成功 
  /// </summary> 
  Success = 1,/// <summary> 
  /// 提示資訊 
  /// </summary> 
  Hint = 0 
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。