如何从 Roslyn 的 AttributeSyntax 获取 AttributeData？

Question

题目如题。

从AttributeSyntax类型的 object 如何获取相关的AttributeData表示以访问元数据？

Answer 1

你需要找到ISymbol的语法被应用到，打电话GetAttributes()并找到返回AttributeData为其ApplicationSyntaxReference您匹配AttributeSyntax 。

Answer 2

@SLaks 的答案是正确的。 下面是一些从AttributeListSyntax检索属性的代码：

using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis;
using System.Collections.Generic;

static class Extensions
{
    public static IReadOnlyList<AttributeData> GetAttributes(this AttributeListSyntax attributes, Compilation compilation)
    {
        // Collect pertinent syntax trees from these attributes
        var acceptedTrees = new HashSet<SyntaxTree>();
        foreach (var attribute in attributes.Attributes)
            acceptedTrees.Add(attribute.SyntaxTree);

        var parentSymbol = attributes.Parent!.GetDeclaredSymbol(compilation)!;
        var parentAttributes = parentSymbol.GetAttributes();
        var ret = new List<AttributeData>();
        foreach (var attribute in parentAttributes)
        {
            if (acceptedTrees.Contains(attribute.ApplicationSyntaxReference!.SyntaxTree))
                ret.Add(attribute);
        }

        return ret;
    }

    public static ISymbol? GetDeclaredSymbol(this SyntaxNode node, Compilation compilation)
    {
        var model = compilation.GetSemanticModel(node.SyntaxTree);
        return model.GetDeclaredSymbol(node);
    }
}