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using System;
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using System.Data;
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using System.Configuration;
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using System.Collections;
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using System.Web;
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using System.Web.Security;
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using System.Web.UI;
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using System.Web.UI.WebControls;
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using System.Web.UI.WebControls.WebParts;
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using System.Web.UI.HtmlControls;
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using System.Text;
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using System.CodeDom.Compiler;
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using Microsoft.CSharp;
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using System.Reflection;
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public partial class Default2 : System.Web.UI.Page
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{
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protected void Page_Load(object sender, EventArgs e)
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{
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TimeSpan Ts = new TimeSpan();
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DateTime dtStar = DateTime.Now;
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Evaluator ev = new Evaluator();
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Response.Write(ev.Eval("2*2*3*10*3.12/811"));
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DateTime dtEnd = DateTime.Now;
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Ts = dtEnd - dtStar;
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Response.Write("<br>" + Ts.TotalMilliseconds.ToString());
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}
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}
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public class Evaluator
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{
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private static CodeDomProvider comp = new CSharpCodeProvider();
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private static CompilerParameters cp = new CompilerParameters();
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private static MethodInfo mi;
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public object Eval(string expression)
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{
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StringBuilder codeBuilder = new StringBuilder();
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codeBuilder.Append("using System;");
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codeBuilder.Append("using Microsoft.CSharp;");
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codeBuilder.Append("");
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codeBuilder.Append("public class Mode");
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codeBuilder.Append("{ ");
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codeBuilder.Append(" public static object Func()");
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codeBuilder.Append("{");
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codeBuilder.Append(" return " + expression + ";");
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codeBuilder.Append(" }");
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codeBuilder.Append(" }");
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cp.ReferencedAssemblies.Add("System.dll");
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cp.GenerateExecutable = false;
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cp.GenerateInMemory = true;
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string code = codeBuilder.ToString();
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string[] stra = new string[] { code };
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CompilerResults cr = comp.CreateCompiler().CompileAssemblyFromSource(cp, code);
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if (cr.Errors.HasErrors)
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{
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return null;
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}
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else
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{
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Assembly a = cr.CompiledAssembly;
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Type t = a.GetType("Mode");
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mi = t.GetMethod("Func", BindingFlags.Static | BindingFlags.Public);
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return mi.Invoke(null, new object[0]);
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}
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}
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}
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