js跨域上传文件 iframe

封装好的jq插件

  (function () {
      var iframe = '<iframe name="jqUploadIframe" style="display: none"></iframe>';
      function getSearchObjct(window) {
          var search;
          try {
              search = window.location.search.substr(1);
          } catch (e) {
              return null;
          }
          if (search == "") return "";
          var keyValue = search.split("&");
          var result = {};
          for (var i = 0; i < keyValue.length; i++) {
              var onek = keyValue[i].split("=");
              result[onek[0]] = decodeURI(onek[1]);
          }
          return result;
      }
      function getRootPath() {
          var curWwwPath = window.document.location.href;
          var pathName = window.document.location.pathname;
          var pos = curWwwPath.indexOf(pathName);
          var localhostPaht = curWwwPath.substring(0, pos);
          var projectName = pathName.substring(0, pathName.substr(1).indexOf('/') + 1);
          return (localhostPaht + projectName);
      }
      var methods = {
          //跨域上传
          crossDomain: function (op) {
              this.attr("target", "jqUploadIframe");
              var $iframe = $(iframe);
              var val = "window.location.href='" + getRootPath() + "/jqUpload32495982348952?data=massage'";
              this.append('<input type="hidden" class="jqUpload-localhostname" ' +
                      'name="uploadCall" value="' + val + '"/>');
              $iframe[0].onload = function () {
                  var searchData = getSearchObjct(this.contentWindow);
                  if (searchData == "") {
                      return;
                  } else if (searchData == null) {
                      op.error();
                  } else if (typeof searchData == "object") {
                      op.success(searchData.data);
                  }
                  $iframe.remove();
                  $(".jqUpload-localhostname").remove();
              }
              this.append($iframe);
              $(this).submit();
          }
      }
      $.fn.jqAjaxUpload = function (op) {
          methods.crossDomain.apply(this, [op])
      }
  })()

前台调用

  //需要提交的表单
  var form = $("<form action='http://www.cnblogs.com/GoCircle/SaveUploadedFile' method='post' enctype='multipart/form-data'></form>");
  form.append($("<input name='formFile' value='" + clearBase64 + "' />"));
  form.append($("<input name='filename' value='" + fileName + "' />"));
  form.append($("<input name='maintainID' value='" + maintainid + "' />"));
  $('#iframeArea').append(form);//必须要追加到当前html页中

  $(form).jqAjaxUpload({
      isCrossDomain: true,
      success: function (result) {
      },
      error: function () {
      }
  })

后台C#  mvc

　　 [AllowAnonymousAttribute]//允许所有请求
　　 [HttpPost]

   public ActionResult SaveUploadedFile(String formFile, String filename, String maintainID)
   {
       //这里必须为这种格式
       return Content("<script>" + Request["uploadCall"].Replace("massage", isSavedSuccessfully) + "</script>");
   }