easyui 动态列

$.post('${createLink(action:"build Columns url ")}', params, function(data){   var columns = [];   var col = [];   for(var i=0; i< data.length; i++){      var v = data;      var c = {title:v.title, field:v.field, width:90};      col.push(c);   }   columns[0] = col;   $('#datagrid').datagrid({columns:columns});},"json");