Roslyn:将使用语句添加到语法树

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;

// 创建一个语法树
SyntaxTree tree = CSharpSyntaxTree.ParseText(@"
using System;

namespace MyNamespace
{
    class MyClass
    {
        static void Main()
        {
            Console.WriteLine(""Hello, World!"");
        }
    }
}");

// 获取根节点
CompilationUnitSyntax root = tree.GetCompilationUnitRoot();

// 创建新的语句节点
StatementSyntax newStatement = SyntaxFactory.ParseStatement("Console.WriteLine(\"New statement\");");

// 将新的语句添加到现有的语法树中的语句列表中
SyntaxList<StatementSyntax> newStatements = root.DescendantNodes().OfType<MethodDeclarationSyntax>()
    .Where(method => method.Identifier.ValueText == "Main")
    .Select(method => method.Body)
    .First()
    .Statements
    .Add(newStatement);

// 更新语法树
CompilationUnitSyntax newRoot = root.ReplaceNode(root.DescendantNodes().OfType<MethodDeclarationSyntax>()
    .Where(method => method.Identifier.ValueText == "Main")
    .Select(method => method.Body)
    .First()
    .Statements, newStatements);

// 格式化语法树
SyntaxNode formattedRoot = newRoot.NormalizeWhitespace();

// 输出更新后的代码
Console.WriteLine(formattedRoot.ToFullString());