code: function exec(scrawlObj) {
      if (scrawlObj.isScrawl) {
          addMaskLayer(lang.scrawlUpLoading);
          var base64 = scrawlObj.getCanvasData();
          if (!!base64) {
              var options = {
                  timeout:100000,
                  onsuccess:function (xhr) {
                      if (!scrawlObj.isCancelScrawl) {
                          var responseObj;
                          responseObj = eval("(" + xhr.responseText + ")");
                          if (responseObj.state == "SUCCESS") {
                              var imgObj = {},
                                  url = editor.options.scrawlUrlPrefix + responseObj.url;
                              imgObj.src = url;
                              imgObj._src = url;
                              imgObj.alt = responseObj.original || '';
                              imgObj.title = responseObj.title || '';
                              editor.execCommand("insertImage", imgObj);
                              dialog.close();
                          } else {
                              alert(responseObj.state);
                          }
  
                      }
                  },
                  onerror:function () {
                      alert(lang.imageError);
                      dialog.close();
                  }
              };
              options[editor.getOpt('scrawlFieldName')] = base64;
  
              var actionUrl = editor.getActionUrl(editor.getOpt('scrawlActionName')),
                  params = utils.serializeParam(editor.queryCommandValue('serverparam')) || '',
                  url = utils.formatUrl(actionUrl + (actionUrl.indexOf('?') == -1 ? '?':'&') + params);
              ajax.request(url, options);
          }
      } else {
          addMaskLayer(lang.noScarwl + "&nbsp;&nbsp;&nbsp;<input type='button' value='" + lang.continueBtn + "'  onclick='removeMaskLayer()'/>");
      }
  }
docs: 执行确认按钮方法