using System;

using System.Linq;

using Microsoft.CodeAnalysis;

using Microsoft.CodeAnalysis.CSharp;

using Microsoft.CodeAnalysis.CSharp.Syntax;

​

namespace RoslynExperiments

{

​

    /*

     //Expected result: 

        - using System.Collections.Generic;

    */

    public class Program

    {

        public static void Main()

        {

            var tree = CSharpSyntaxTree.ParseText(@" 

                using System;

                using System.Collections.Generic;

                using System.Text;

                namespace MyNamespace

                {               

                    public class MyClass1

                    { 

                        public void MyMethod() 

                        { 

                            List<int> list = new List<int>();

                        } 

                    }

                    public class MyClass2

                    {                   

                        public void MyMethod() 

                        { 

                            StringBuilder sb = new StringBuilder();

                        } 

                    }

                }");

​

            var syntaxRoot = tree.GetRoot();

​

            var Mscorlib = MetadataReference.CreateFromFile(typeof(object).Assembly.Location);

            var compilation = CSharpCompilation.Create("MyCompilation", syntaxTrees: new[] { tree }, references: new[] { Mscorlib });

            var model = compilation.GetSemanticModel(tree);

​

            var MyNamespace = syntaxRoot.DescendantNodes().OfType<NamespaceDeclarationSyntax>().First();

            var MyClass1 = MyNamespace.DescendantNodes().OfType<ClassDeclarationSyntax>().First(x => x.Identifier.Text == "MyClass1");

            var MyClass2 = MyNamespace.DescendantNodes().OfType<ClassDeclarationSyntax>().First(x => x.Identifier.Text == "MyClass1");

​

            var result = FindUsedUsings(model, MyClass1);

​

            Console.WriteLine(result);

        }

        private static string FindUsedUsings(SemanticModel model, SyntaxNode node)

        {

            throw new NotImplementedException();    

        }

    }

}

​