解析Rss和Atom订阅

想着闲的没事的时候重构一下朋友圈的项目，打算改成前后端分离的架构，前端使用Blazor webassembly 后端使用ASP.NET Core Web Api。先写一个简单的Rss和atom订阅解析功能~

using System.Xml;
using Moment.Shared.DBModel;

namespace Moment.Core;

/// <summary>
/// 核心模块
/// </summary>
public static class Core
{
    /// <summary>
    /// 获取Atom的订阅内容
    /// </summary>
    /// <param name="url">链接</param>
    /// <returns></returns>
    public static async Task<List<FeedItem>> Atom(string url)
    {
        var feedItems = new List<FeedItem>();
        var httpClient = new HttpClient();
        var feed = await httpClient.GetStringAsync(url);
        var xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(feed);
        var nsManager = new XmlNamespaceManager(xmlDoc.NameTable);
        nsManager.AddNamespace("atom", "http://www.w3.org/2005/Atom");
        var entries = xmlDoc.SelectNodes("//atom:entry", nsManager);
        foreach (XmlNode entry in entries!)
        {
            var title = entry.SelectSingleNode("atom:title", nsManager)?.InnerText;
            var link = entry.SelectSingleNode("atom:link", nsManager)?.Attributes!["href"]!.Value;
            var summary = entry.SelectSingleNode("atom:summary", nsManager)?.InnerText;
            var content = entry.SelectSingleNode("atom:content", nsManager)?.InnerText;
            var published = entry.SelectSingleNode("atom:published", nsManager)?.InnerText;
            feedItems.Add(new FeedItem
            {
                Title = title, Link = link, Content = content, Summary = summary, Published = published
            });
        }

        return feedItems;
    }

    /// <summary>
    /// 获取Rss2.0的订阅内容
    /// </summary>
    /// <param name="url">链接</param>
    /// <returns></returns>
    public static async Task<List<FeedItem>> Rss(string url)
    {
        var feedItems = new List<FeedItem>();
        var httpClient = new HttpClient();
        var feed = await httpClient.GetStringAsync(url);
        var xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(feed);
        var nsManager = new XmlNamespaceManager(xmlDoc.NameTable);
        nsManager.AddNamespace("rss", "http://rss2.org/schema/");
        nsManager.AddNamespace("content", "http://purl.org/rss/1.0/modules/content/");
        var entries = xmlDoc.SelectNodes("//rss/channel/item", nsManager);
        foreach (XmlNode entry in entries!)
        {
            var title = entry.SelectSingleNode("./title", nsManager)?.InnerText;
            var link = entry.SelectSingleNode("./link", nsManager)?.InnerText;
            var summary = entry.SelectSingleNode("./description", nsManager)?.InnerText;
            var content = entry.SelectSingleNode("./content:encoded", nsManager)?.InnerText;
            var published = entry.SelectSingleNode("./pubDate", nsManager)?.InnerText; // Added line to ge
            feedItems.Add(new FeedItem
            {
                Title = title, Link = link, Content = content, Summary = summary, Published = published
            });
        }

        return feedItems;
    }
}