c#动态构建代码树

桃扇骨 2022-08-13 14:48 202阅读 0赞

using System;
    using System.IO;
    using System.Text;
    using System.CodeDom;
    using System.CodeDom.Compiler;
    using System.Diagnostics;
    
    partial class HelloWorldCodeDOM
    {
        static void Main()
        {
            CodeNamespace prgNamespace = BuildProgram();
            var compilerOptions = new CodeGeneratorOptions()
            {
                IndentString = "  ",
                BracingStyle = "C",
                BlankLinesBetweenMembers = false
            };
            var codeText = new StringBuilder();
            using (var codeWriter = new StringWriter(codeText))
            {
                CodeDomProvider.CreateProvider("c#")
                  .GenerateCodeFromNamespace(
                    prgNamespace, codeWriter, compilerOptions);
            }
            var script = codeText.ToString();
            Console.WriteLine(script);
            if (Debugger.IsAttached)
                Console.ReadLine();
        }
    }
    
    partial class HelloWorldCodeDOM
    {
        static CodeNamespace BuildProgram()
        {
            var ns = new CodeNamespace("MetaWorld");
            var systemImport = new CodeNamespaceImport("System");
            ns.Imports.Add(systemImport);
            var programClass = new CodeTypeDeclaration("Program");
            ns.Types.Add(programClass);
            var methodMain = new CodeMemberMethod
            {
                Attributes = MemberAttributes.Static,
                Name = "Main"
            };
            methodMain.Statements.Add(
                new CodeMethodInvokeExpression(
                    new CodeSnippetExpression("Console"),
                    "WriteLine",
                    new CodePrimitiveExpression("Hello, world!")
                )
            );
            programClass.Members.Add(methodMain);
            return ns;
        }
    }

partial class HelloWorldCodeDOM
    {
        //由内而外，与置顶向下设计相反（当然，下面代码可以反过来）
        static CodeNamespace BuildProgram()
        {
            var methodMain = new CodeMemberMethod                   //定义成员方法
            {
                Attributes = MemberAttributes.Static,               //成员方法特性
                Name = "Main"                                       //方法名
            };
    
            methodMain.Statements.Add(                              //添加成员方法的代码表达式
                //构建代码表达式
                new CodeMethodInvokeExpression(
                    new CodeSnippetExpression("Console"),
                    "WriteLine",
                    new CodePrimitiveExpression("Hello, world!")
                )
            );
    
            var programClass = new CodeTypeDeclaration("Program");  //类对象
            programClass.Members.Add(methodMain);
    
            var ns = new CodeNamespace("MetaWorld");                //命名空间
            ns.Imports.Add(new CodeNamespaceImport("System"));      //添加引用
            ns.Types.Add(programClass);                             //添加类
            //ns.Types.Add(new CodeTypeDeclaration("TestClass"));   //添加类
    
            return ns;
        }
    }