c# JScriptProvider包装

using System;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Web.UI;
using Microsoft.JScript;

namespace HuaTong.General.Utility
{
    /// <summary>
    /// JScriptProvider包装
    /// </summary>
    public static class JScript
    {
        private static object js = null;
        private static Type jsType = null;
        private static readonly string jsSource =
          @"package JScript  
          {  
             class JScript  
             {  
              public function Eval(expr : String) : Object  
              {  
               return eval(expr);  
              }  
             }  
          }";
        /// <summary>
        /// 构造javascript运行时对象
        /// </summary>
        static JScript()
        {
            JScriptCodeProvider compiler = new JScriptCodeProvider();
            CompilerParameters parameters = new CompilerParameters();
            parameters.GenerateInMemory = true;
            CompilerResults results = compiler.CompileAssemblyFromSource(parameters, jsSource);

            Assembly assembly = results.CompiledAssembly;
            jsType = assembly.GetType("JScript.JScript");

            js = Activator.CreateInstance(jsType);
        }
        /// <summary>
        /// 获取表达式的值
        /// </summary>
        /// <returns></returns>
        public static int EvalToInt32(string code)
        {
            string s = EvalToString(code);
            return int.Parse(s);
        }
        /// <summary>
        /// 获取表达式的值
        /// </summary>
        /// <returns></returns>
        public static double EvalToDouble(string code)
        {
            string s = EvalToString(code);
            return double.Parse(s);
        }
        /// <summary>
        /// 获取表达式的值
        /// </summary>
        /// <returns></returns>
        public static string EvalToString(string code)
        {
            object o = EvalToObject(code);
            return o.ToString();
        }
        /// <summary>
        /// 获取表达式的值
        /// </summary>
        /// <returns></returns>
        public static object EvalToObject(string code)
        {
            return jsType.InvokeMember("Eval", BindingFlags.InvokeMethod, null, js,
                  new object[] { code });
        }
    }
}