using System;
using System.Reflection;

namespace CsharpHttpHelper.Helper
{
	/// <summary>
	/// 用户执行JS的方法  Copyright：http://www.httphelper.com/
	/// </summary>
	internal class ExecJsHelper
	{
		private static Type type = Type.GetTypeFromProgID("ScriptControl");

		/// <summary>
		/// 直接调用JS方法并获取返回的值
		/// </summary>
		/// <param name="strJs">要执行的JS代码</param>
		/// <param name="main">要调用的方法名</param>
		/// <returns>执行结果</returns>
		internal static string JavaScriptEval(string strJs, string main)
		{
			object scriptControl = GetScriptControl();
			SetScriptControlType(strJs, scriptControl);
			return type.InvokeMember("Eval", BindingFlags.InvokeMethod, null, scriptControl, new object[1]
			{
				main
			}).ToString();
		}

		/// <summary>
		/// 获取ScriptControl接口类
		/// </summary>
		/// <param name="strJs">JS</param>
		/// <param name="obj">对象</param>
		/// <returns>Type</returns>
		private static Type SetScriptControlType(string strJs, object obj)
		{
			type.InvokeMember("Language", BindingFlags.SetProperty, null, obj, new object[1]
			{
				"JScript"
			});
			type.InvokeMember("AddCode", BindingFlags.InvokeMethod, null, obj, new object[1]
			{
				strJs
			});
			return type;
		}

		/// <summary>
		/// 获取ScriptControl接口对象
		/// </summary>
		/// <returns>ScriptControl对象</returns>
		private static object GetScriptControl()
		{
			return Activator.CreateInstance(type);
		}
	}
}