如果将字符串的内容作为代码执行

Question

例如:b="string a;"；
如何 通过执行变量b 从而达到程序自动定义变量a ？？？

Answer 1

动态编译。
例：获取字符串所表示的逻辑意义 /*****************************************************************
    ** 文件名:       Eval.cs
    ** Copyright (c) 1999 -2003 
    ** 创建人:       Phoenix
    ** 创建日期: 
    ** 修改人:
    ** 修改日期: 
    ** 描 述:         获取字符串所表示的逻辑意义
    ** 版 本:1.0
    ******************************************************************/
    public class Eval
        {
        public static object GetValue(string value)
            {
            string codeSnippet = "using System; " + "\r\n" +
                                            "namespace CzG {" + "\r\n" +
                                                        " public class Eval" + "\r\n" +
                                                        " {" + "\r\n" +
                                            "       public Eval(){} " + "\r\n" +
                                                        "  public object GetValue()" + "\r\n" +
                                                        "  {" + "\r\n" +
                                                        "   return " + value + ";" + "\r\n" +
                                                        "  }" + "\r\n" +
                                                  " } }";
      
            CodeSnippetCompileUnit unit = new CodeSnippetCompileUnit(codeSnippet);
            CodeDomProvider compiler=new CSharpCodeProvider() ;
            //ICodeCompiler compiler = new CSharpCodeProvider().CreateCompiler();
            string[] referenceAssemblies={"System.dll"};
            CompilerParameters para = new CompilerParameters(referenceAssemblies ,"Eval.dll",false );
            //para.ReferencedAssemblies.Add("System.dll");
            para.GenerateInMemory = true;
            para.GenerateExecutable = false;
            //para.OutputAssembly = "Eval.dll";            Assembly asm = compiler.CompileAssemblyFromDom(para, unit).CompiledAssembly;            Type type = asm.GetType("CzG.Eval");
            MethodInfo mi = type.GetMethod("GetValue", BindingFlags.Public | BindingFlags.Instance);            object obj = asm.CreateInstance("CzG.Eval");
            object ret = mi.Invoke(obj, null);
            return ret;
            }
        }