如何使用roslyn获取表达式中的预期类型？

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

public class ExpressionTypeAnalyzer
{
    public static ITypeSymbol GetExpectedType(string expression)
    {
        // 创建语法树
        SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(expression);

        // 获取语法树根节点
        SyntaxNode root = syntaxTree.GetRoot();

        // 遍历语法树
        foreach (var node in root.DescendantNodes())
        {
            // 判断节点是否为表达式节点
            if (node is ExpressionSyntax expressionNode)
            {
                // 获取表达式的预期类型
                SemanticModel semanticModel = GetSemanticModel(syntaxTree);
                return semanticModel.GetTypeInfo(expressionNode).Type;
            }
        }

        return null;
    }

    private static SemanticModel GetSemanticModel(SyntaxTree syntaxTree)
    {
        // 创建编译上下文
        CSharpCompilation compilation = CSharpCompilation.Create("Temp")
            .AddReferences(MetadataReference.CreateFromFile(typeof(object).Assembly.Location))
            .AddSyntaxTrees(syntaxTree);

        // 获取语义模型
        return compilation.GetSemanticModel(syntaxTree);
    }
}