将List 集合 转换为Jsion 数据 + 页面JS 调用

        /// <summary>  
        /// List转换Jsion 数据  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="jsonName"></param>  
        /// <param name="IL"></param>  
        /// <returns></returns>
        public static string ObjectToJson<T>(IList<T> IL)  
        {  
            StringBuilder Json = new StringBuilder();  
            Json.Append("[");  
            if (IL.Count > 0)  
            {  
                for (int i = 0; i < IL.Count; i++)  
                {  
                    T obj = Activator.CreateInstance<T>();  
                    Type type = obj.GetType();  
                    System.Reflection.PropertyInfo[] pis = type.GetProperties();  
                    Json.Append("{");  
                    for (int j = 0; j < pis.Length; j++)  
                    {  
                        Json.Append("\"" + pis[j].Name.ToString() + "\":\"" + pis[j].GetValue(IL[i], null) + "\"");  
                        if (j < pis.Length - 1)  
                        {  
                            Json.Append(",");  
                        }  
                    }  
                    Json.Append("}");  
                    if (i < IL.Count - 1)  
                    {  
                        Json.Append(",");  
                    }  
                }  
            }  
            Json.Append("]");  
            return Json.ToString();  
        }  

$.ajax({   
            type: "get",   
            url: "UserMethod.ashx",   
            cache: false,   
            data: "MID=GetCity&ProId="+id,  
            dataType: 'text',   
            success: function(data){   
               var j = eval(data)  
               var subSel=$("#sel_city");     
               subSel.prepend("<option value='0'>请选择</option>");  
                 
               $.each(j,function( i,value){  
                   
                var subOp = $("<option>");   
                subOp.attr("id",'ocity_' + value.Id);  
                subOp.attr("value",value.Id);  
                subOp.html(value.Name);   
                  
                subSel.attr("onchange",'javascript:checkCityValue();');  
                  
                subSel.append(subOp)  
                  
                isTrue=false;  
                });  
            },    
            error: function(){   
                  return;   
                }   
            });