C\#동적 실행 문자열(동적 생 성 코드)의 인 스 턴 스 코드

using System;
using System.Data;
using System.Configuration;
using System.Text;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;
namespace EvalGuy
{
    /// <summary>
    ///                   
    ///      ，     ！
    /// </summary>
    public class Evaluator
    {
        #region     
        /// <summary>
        ///          
        /// </summary>
        /// <param name="items">
        ///         
        /// </param>
        public Evaluator(EvaluatorItem[] items)
        {
            ConstructEvaluator(items);        //               
        }
        /// <summary>
        ///          
        /// </summary>
        /// <param name="returnType">     </param>
        /// <param name="expression">     </param>
        /// <param name="name">       </param>
        public Evaluator(Type returnType, string expression, string name)
        {
            //          
            EvaluatorItem[] items = { new EvaluatorItem(returnType, expression, name) };
            ConstructEvaluator(items);        //               
        }
        /// <summary>
        ///          
        /// </summary>
        /// <param name="item">       </param>
        public Evaluator(EvaluatorItem item)
        {
            EvaluatorItem[] items = { item };//                   
            ConstructEvaluator(items);        //               
        }
        /// <summary>
        ///          
        /// </summary>
        /// <param name="items">        </param>
        private void ConstructEvaluator(EvaluatorItem[] items)
        {
            //  C#     
            ICodeCompiler comp = (new CSharpCodeProvider().CreateCompiler());
            //        
            CompilerParameters cp = new CompilerParameters();
            cp.ReferencedAssemblies.Add("system.dll");                //      system.dll    
            cp.ReferencedAssemblies.Add("system.data.dll");            //      system.data.dll    
            cp.ReferencedAssemblies.Add("system.xml.dll");            //      system.xml.dll    
            cp.GenerateExecutable = false;                            //        
            cp.GenerateInMemory = true;                                //      
            StringBuilder code = new StringBuilder();                //     
            /*
             *               
             */
            code.Append("using System; /n");
            code.Append("using System.Data; /n");
            code.Append("using System.Data.SqlClient; /n");
            code.Append("using System.Data.OleDb; /n");
            code.Append("using System.Xml; /n");
            code.Append("namespace EvalGuy { /n");                    //          EvalGuy，      
            code.Append("  public class _Evaluator { /n");            //   _Evaluator  ，              
            foreach (EvaluatorItem item in items)                //            
            {
                code.AppendFormat("    public {0} {1}() ",            //          
                                  item.ReturnType.Name,                //                      
                                  item.Name);                        //                       
                code.Append("{ ");                                    //        
                code.AppendFormat("return ({0});", item.Expression);//     ，                  
                code.Append("}/n");                                    //        
            }
            code.Append("} }");                                    //              
            //            
            CompilerResults cr = comp.CompileAssemblyFromSource(cp, code.ToString());
            if (cr.Errors.HasErrors)                            //     
            {
                StringBuilder error = new StringBuilder();            //         
                error.Append("         : ");                //      
                foreach (CompilerError err in cr.Errors)            //            
                {
                    error.AppendFormat("{0}/n", err.ErrorText);        //       ，       
                }
                throw new Exception("    : " + error.ToString());//    
            }
            Assembly a = cr.CompiledAssembly;                        //           
            _Compiled = a.CreateInstance("EvalGuy._Evaluator");        //           EvalGuy._Evaluator    
        }
        #endregion
        #region     
        /// <summary>
        ///            
        /// </summary>
        /// <param name="name">       </param>
        /// <returns>    </returns>
        public int EvaluateInt(string name)
        {
            return (int)Evaluate(name);
        }
        /// <summary>
        ///              
        /// </summary>
        /// <param name="name">       </param>
        /// <returns>    </returns>
        public string EvaluateString(string name)
        {
            return (string)Evaluate(name);
        }
        /// <summary>
        ///             
        /// </summary>
        /// <param name="name">       </param>
        /// <returns>    </returns>
        public bool EvaluateBool(string name)
        {
            return (bool)Evaluate(name);
        }
        /// <summary>
        ///         object   
        /// </summary>
        /// <param name="name">       </param>
        /// <returns>    </returns>
        public object Evaluate(string name)
        {
            MethodInfo mi = _Compiled.GetType().GetMethod(name);//   _Compiled          name       
            return mi.Invoke(_Compiled, null);                    //   mi       
        }
        #endregion
        #region     
        /// <summary>
        ///            
        /// </summary>
        /// <param name="code">       </param>
        /// <returns>    </returns>
        static public int EvaluateToInteger(string code)
        {
            Evaluator eval = new Evaluator(typeof(int), code, staticMethodName);//   Evaluator     
            return (int)eval.Evaluate(staticMethodName);                        //         
        }
        /// <summary>
        ///              
        /// </summary>
        /// <param name="code">       </param>
        /// <returns>    </returns>
        static public string EvaluateToString(string code)
        {
            Evaluator eval = new Evaluator(typeof(string), code, staticMethodName);//   Evaluator     
            return (string)eval.Evaluate(staticMethodName);                        //           
        }
        /// <summary>
        ///             
        /// </summary>
        /// <param name="code">       </param>
        /// <returns>    </returns>
        static public bool EvaluateToBool(string code)
        {
            Evaluator eval = new Evaluator(typeof(bool), code, staticMethodName);//   Evaluator     
            return (bool)eval.Evaluate(staticMethodName);                        //          
        }
        /// <summary>
        ///          object   
        /// </summary>
        /// <param name="code">       </param>
        /// <returns>    </returns>
        static public object EvaluateToObject(string code)
        {
            Evaluator eval = new Evaluator(typeof(object), code, staticMethodName);//   Evaluator     
            return eval.Evaluate(staticMethodName);                                //      object    
        }
        #endregion
        #region     
        /// <summary>
        ///             
        /// </summary>
        private const string staticMethodName = "__foo";
        /// <summary>
        ///           ，              
        /// </summary>
        object _Compiled = null;
        #endregion
    }
    /// <summary>
    ///        （         ）
    /// </summary>
    public class EvaluatorItem
    {
        /// <summary>
        ///      
        /// </summary>
        public Type ReturnType;
        /// <summary>
        ///      
        /// </summary>
        public string Expression;
        /// <summary>
        ///        
        /// </summary>
        public string Name;
        /// <summary>
        ///            
        /// </summary>
        /// <param name="returnType">     </param>
        /// <param name="expression">     </param>
        /// <param name="name">       </param>
        public EvaluatorItem(Type returnType, string expression, string name)
        {
            ReturnType = returnType;
            Expression = expression;
            Name = name;
        }
    }
}