SOMS/test/MathConsoleApp/MathExpress.cs

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.Emit;
using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Loader;
using System.Text;

namespace MathConsoleApp
{
    /// <summary>
    /// 本类用来将字符串转为可执行文本并执行
    /// </summary>
    public class MyEvaluator
    {
        #region 构造函数

        /// <summary>
        /// 可执行串的构造函数
        /// </summary>
        /// <param name="items">
        /// 可执行字符串数组
        /// </param>
        public MyEvaluator(EvaluatorItem[] items)
        {
            ConstructEvaluator(items);      //调用解析字符串构造函数进行解析
        }

        /// <summary>
        /// 可执行串的构造函数
        /// </summary>
        /// <param name="returnType">返回值类型</param>
        /// <param name="expression">执行表达式</param>
        /// <param name="name">执行字符串名称</param>
        public MyEvaluator(Type returnType, string expression, string name)
        {
            //创建可执行字符串数组
            EvaluatorItem[] items = { new EvaluatorItem(returnType, expression, name) };
            ConstructEvaluator(items);      //调用解析字符串构造函数进行解析
        }

        /// <summary>
        /// 可执行串的构造函数
        /// </summary>
        /// <param name="item">可执行字符串项</param>
        public MyEvaluator(EvaluatorItem item)
        {
            EvaluatorItem[] items = { item };//将可执行字符串项转为可执行字符串项数组
            ConstructEvaluator(items);      //调用解析字符串构造函数进行解析
        }

        /// <summary>
        /// 解析字符串构造函数
        /// </summary>
        /// <param name="items">待解析字符串数组</param>
        private void ConstructEvaluator_net46(EvaluatorItem[] items)
        {
            string sysFile = typeof(Enumerable).Assembly.Location;
            string sysDir = Directory.GetParent(sysFile).FullName;
            //创建C#编译器实例
            CodeDomProvider provider = CodeDomProvider.CreateProvider("C#");
            //CodeDomProvider provider = new CSharpCodeProvider();
            //过时了
            //ICodeCompiler comp = provider.CreateCompiler();

            //编译器的传入参数
            CompilerParameters cp = new CompilerParameters();
            cp.ReferencedAssemblies.Add(Path.Combine(sysDir, "System.dll"));              //添加程序集 system.dll 的引用
            cp.ReferencedAssemblies.Add(Path.Combine(sysDir, "System.Data.dll"));         //添加程序集 system.data.dll 的引用
            cp.ReferencedAssemblies.Add(Path.Combine(sysDir, "System.Xml.dll"));          //添加程序集 system.xml.dll 的引用
            cp.GenerateExecutable = false;                          //不生成可执行文件
            cp.GenerateInMemory = true;                             //在内存中运行

            StringBuilder code = new StringBuilder();               //创建代码串
            /*
             *  添加常见且必须的引用字符串
             */
            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 SSEC.Math { \n");                  //生成代码的命名空间为EvalGuy，和本代码一样

            code.Append("  public class _Evaluator { \n");          //产生 _Evaluator 类，所有可执行代码均在此类中运行
            foreach (EvaluatorItem item in items)               //遍历每一个可执行字符串项
            {
                code.AppendFormat("    public {0} {1}() ",          //添加定义公共函数代码
                                  item.ReturnType.Name,             //函数返回值为可执行字符串项中定义的返回值类型
                                  item.Name);                       //函数名称为可执行字符串项中定义的执行字符串名称
                code.Append("{ ");                                  //添加函数开始括号
                code.AppendFormat("return ({0});", item.Expression);//添加函数体，返回可执行字符串项中定义的表达式的值
                code.Append("} \n");                                 //添加函数结束括号
            }
            code.Append("} }");                                 //添加类结束和命名空间结束括号

            //得到编译器实例的返回结果
            CompilerResults cr = provider.CompileAssemblyFromSource(cp, code.ToString());//comp

            if (cr.Errors.HasErrors)                            //如果有错误
            {
                StringBuilder error = new StringBuilder();          //创建错误信息字符串
                error.Append("编译有错误的表达式: ");                //添加错误文本
                foreach (CompilerError err in cr.Errors)            //遍历每一个出现的编译错误
                {
                    error.AppendFormat("{0}\n", err.ErrorText);     //添加进错误文本，每个错误后换行
                }
                throw new Exception("编译错误: " + error.ToString());//抛出异常
            }
            Assembly a = cr.CompiledAssembly;                       //获取编译器实例的程序集
            _Compiled = a.CreateInstance("SSEC.Math._Evaluator");     //通过程序集查找并声明 SSEC.Math._Evaluator 的实例
        }

        /// <summary>
        /// 解析字符串构造函数
        /// </summary>
        /// <param name="items">待解析字符串数组</param>
        private void ConstructEvaluator(EvaluatorItem[] items)
        {
            string sysFile = typeof(Enumerable).Assembly.Location;
            string sysDir = Directory.GetParent(sysFile).FullName;
            List<MetadataReference> references = new List<MetadataReference>();
            references.Add(MetadataReference.CreateFromFile(Path.Combine(sysDir, "System.dll")));
            references.Add(MetadataReference.CreateFromFile(Path.Combine(sysDir, "System.Data.dll")));
            references.Add(MetadataReference.CreateFromFile(Path.Combine(sysDir, "System.Xml.dll")));

            StringBuilder code = new StringBuilder();               //创建代码串
            /*
             *  添加常见且必须的引用字符串
             */
            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 SSEC.Math { \n");                  //生成代码的命名空间为EvalGuy，和本代码一样

            code.Append("  public class _Evaluator { \n");          //产生 _Evaluator 类，所有可执行代码均在此类中运行
            foreach (EvaluatorItem item in items)               //遍历每一个可执行字符串项
            {
                code.AppendFormat("    public {0} {1}() ",          //添加定义公共函数代码
                                  item.ReturnType.Name,             //函数返回值为可执行字符串项中定义的返回值类型
                                  item.Name);                       //函数名称为可执行字符串项中定义的执行字符串名称
                code.Append("{ ");                                  //添加函数开始括号
                code.AppendFormat("return ({0});", item.Expression);//添加函数体，返回可执行字符串项中定义的表达式的值
                code.Append("} \n");                                 //添加函数结束括号
            }
            code.Append("}}");                                 //添加类结束和命名空间结束括号
            string assemblyName = "SSEC.Math";
            SyntaxTree tree = SyntaxFactory.ParseSyntaxTree(code.ToString());
            CSharpCompilation compilation = CSharpCompilation.Create(assemblyName);
            compilation.WithOptions(
                    new CSharpCompilationOptions(
                            OutputKind.DynamicallyLinkedLibrary
                            , usings: null
                            , optimizationLevel: OptimizationLevel.Debug
                            , checkOverflow: false
                            , allowUnsafe: true
                            , platform: Platform.AnyCpu
                            , warningLevel: 4
                            , xmlReferenceResolver: null)
                );
            compilation.AddReferences(references);
            compilation.AddSyntaxTrees(tree);

            using (var ms = new MemoryStream())
            {
                EmitResult result = compilation.Emit(ms);

                if (!result.Success)
                {
                    IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
                        diagnostic.IsWarningAsError ||
                        diagnostic.Severity == DiagnosticSeverity.Error);

                    foreach (Diagnostic diagnostic in failures)
                    {
                        Console.Error.WriteLine("\t{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
                    }
                }
                else
                {
                    ms.Seek(0, SeekOrigin.Begin);
                    Assembly assembly = AssemblyLoadContext.Default.LoadFromStream(ms);
                    //var type = assembly.GetTypes().Where(x => x.IsImplementlInterface(typeof(IProtocolExecutor))).FirstOrDefault();
                    //_Compiled=(IProtocolExecutor)Activator.CreateInstance(type, newProtocol.ProtocolID, newProtocol.Version);  //实例化解析类
                    _Compiled = assembly.CreateInstance("SSEC.Math._Evaluator");
                }
            }
        }

        #endregion 构造函数

        #region 公有成员

        /// <summary>
        /// 执行字符串并返回整型值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public int EvaluateInt(string name)
        {
            return (int)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返回双精度值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public double EvaluateDouble(string name)
        {
            return (double)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返回长整型数值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public long EvaluateLong(string name)
        {
            return (long)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返回十进制数值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public decimal EvaluateDecimal(string name)
        {
            return (decimal)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返回字符串型值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public string EvaluateString(string name)
        {
            return (string)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返回布尔型值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public bool EvaluateBool(string name)
        {
            return (bool)Evaluate(name);
        }

        /// <summary>
        /// 执行字符串并返 object 型值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        public object Evaluate(string name)
        {
            MethodInfo mi = _Compiled.GetType().GetMethod(name);//获取 _Compiled 所属类型中名称为 name 的方法的引用
            return mi.Invoke(_Compiled, null);                  //执行 mi 所引用的方法
        }

        #endregion 公有成员

        #region 静态成员

        /// <summary>
        /// 执行表达式并返回整型值
        /// </summary>
        /// <param name="code">要执行的表达式</param>
        /// <returns>运算结果</returns>
        static public int EvaluateToInteger(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(int), code, staticMethodName);//生成 Evaluator 类的对像
            return (int)eval.Evaluate(staticMethodName);                        //执行并返回整型数据
        }

        /// <summary>
        /// 执行表达式并返回双精度值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        static public double EvaluateToDouble(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(double), code, staticMethodName);//生成 Evaluator 类的对像
            return (double)eval.Evaluate(staticMethodName);
        }

        /// <summary>
        /// 执行表达式并返回长整型数值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        static public long EvaluateToLong(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(long), code, staticMethodName);//生成 Evaluator 类的对像
            return (long)eval.Evaluate(staticMethodName);
        }

        /// <summary>
        /// 执行表达式并返回十进制数值
        /// </summary>
        /// <param name="name">执行字符串名称</param>
        /// <returns>执行结果</returns>
        static public decimal EvaluateToDecimal(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(decimal), code, staticMethodName);//生成 Evaluator 类的对像
            return (decimal)eval.Evaluate(staticMethodName);
        }

        /// <summary>
        /// 执行表达式并返回字符串型值
        /// </summary>
        /// <param name="code">要执行的表达式</param>
        /// <returns>运算结果</returns>
        static public string EvaluateToString(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(string), code, staticMethodName);//生成 Evaluator 类的对像
            return (string)eval.Evaluate(staticMethodName);                     //执行并返回字符串型数据
        }

        /// <summary>
        /// 执行表达式并返回布尔型值
        /// </summary>
        /// <param name="code">要执行的表达式</param>
        /// <returns>运算结果</returns>
        static public bool EvaluateToBool(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(bool), code, staticMethodName);//生成 Evaluator 类的对像
            return (bool)eval.Evaluate(staticMethodName);                       //执行并返回布尔型数据
        }

        /// <summary>
        /// 执行表达式并返回 object 型值
        /// </summary>
        /// <param name="code">要执行的表达式</param>
        /// <returns>运算结果</returns>
        static public object EvaluateToObject(string code)
        {
            MyEvaluator eval = new MyEvaluator(typeof(object), code, staticMethodName);//生成 Evaluator 类的对像
            return eval.Evaluate(staticMethodName);                             //执行并返回 object 型数据
        }

        #endregion 静态成员

        #region 私有成员

        /// <summary>
        /// 静态方法的执行字符串名称
        /// </summary>
        private const string staticMethodName = "__foo";

        /// <summary>
        /// 用于动态引用生成的类，执行其内部包含的可执行字符串
        /// </summary>
        private object _Compiled = null;

        #endregion 私有成员
    }

    /// <summary>
    /// 可执行字符串项（即一条可执行字符串）
    /// </summary>
    public class EvaluatorItem
    {
        /// <summary>
        /// 返回值类型
        /// </summary>
        public Type ReturnType;

        /// <summary>
        /// 执行表达式
        /// </summary>
        public string Expression;

        /// <summary>
        /// 执行字符串名称
        /// </summary>
        public string Name;

        /// <summary>
        /// 可执行字符串项构造函数
        /// </summary>
        /// <param name="returnType">返回值类型</param>
        /// <param name="expression">执行表达式</param>
        /// <param name="name">执行字符串名称</param>
        public EvaluatorItem(Type returnType, string expression, string name)
        {
            ReturnType = returnType;
            Expression = expression;
            Name = name;
        }
    }
}