使用AngleSharp库可以将HTML属性转换为字典。以下是一个示例代码：

using AngleSharp.Dom;
using AngleSharp.Html.Dom;
using System;
using System.Collections.Generic;

public class Program
{
    public static void Main(string[] args)
    {
        string html = "
Hello World
";
        
        var parser = new AngleSharp.Html.Parser.HtmlParser();
        IHtmlDocument document = parser.ParseDocument(html);
        
        IElement divElement = document.QuerySelector("div");
        IDictionary attributes = GetAttributes(divElement);
        
        foreach (var attribute in attributes)
        {
            Console.WriteLine($"Attribute: {attribute.Key}, Value: {attribute.Value}");
        }
    }
    
    public static IDictionary GetAttributes(IElement element)
    {
        var attributes = new Dictionary();
        
        foreach (var attribute in element.Attributes)
        {
            attributes.Add(attribute.Name, attribute.Value);
        }
        
        return attributes;
    }
}

在上面的示例中，我们首先使用AngleSharp的HTML解析器将HTML字符串解析为IHtmlDocument对象。然后，使用QuerySelector方法选择要获取属性的元素（在这里是

Attribute: id, Value: myDiv
Attribute: class, Value: myClass
Attribute: data-custom, Value: 123