tede/gx_api/GxPress/Service/GxPress.Service.Implement/Epub/EpubService.cs

using System.Collections.Generic;
using GxPress.Request.Media;
using GxPress.Result.Category;
using GxPress.Result.Media;
using GxPress.Service.Interface.Epub;
using GxPress.Repository.Interface.Media;
using VersOne.Epub;
using System;
using System.Threading.Tasks;

namespace GxPress.Service.Implement.Epub
{
    public class EpubService : IEpubService
    {
        private readonly IMediaRepository mediaRepository;
        public EpubService(IMediaRepository mediaRepository)
        {
            this.mediaRepository = mediaRepository;
        }
        /// <summary>
        /// 获取书籍目录
        /// </summary>
        public List<BookCatalogResult> GetCatalog(string path)
        {
            var result = new List<BookCatalogResult>();
            EpubBook epubBook = EpubReader.ReadBook(path);
            int i = 1;
            // 目录
            //列举章节
            foreach (EpubNavigationItem chapter in epubBook.Navigation)
            {
                //本章标题
                var bookCatalog = new BookCatalogResult();
                bookCatalog.Id = i;
                bookCatalog.CatalogNameg = chapter.Title;
                bookCatalog.CatalogId = chapter.HtmlContentFile.FileName;
                result.Add(bookCatalog);
                //嵌套章节
                List<EpubNavigationItem> subChapters = chapter.NestedItems;
                foreach (var item in subChapters)
                {
                    bookCatalog = new BookCatalogResult();
                    bookCatalog.CatalogNameg = item.Title;
                    bookCatalog.CatalogId = item.HtmlContentFile.FileName;
                    bookCatalog.ParentId = i;
                    result.Add(bookCatalog);
                }
                i++;
            }
            return result;
        }
        /// <summary>
        /// 获取章节内容
        /// </summary>
        /// <returns></returns>
        public async Task<string> GetBookCatalogContent(BookCatalogRequest request)
        {
            if (string.IsNullOrEmpty(request.Path))
                return string.Empty;
            //获取media
            var media = await mediaRepository.GetAsync(request.MediaId);
            var sectionValue = 0;
            if (media.FreeProportion > 0)
            {
                var freeProportion = media.FreeProportion / 100;
                var catalogs = GetCatalog(request.Path);
                sectionValue = Convert.ToInt32(catalogs.Count * freeProportion);
            }
            EpubBook epubBook = EpubReader.ReadBook(request.Path);
            string htmlContent = string.Empty;
            int i = 0;
            foreach (EpubTextContentFile textContentFile in epubBook.ReadingOrder)
            {
                if (i >= sectionValue && sectionValue > 0)
                    return "";
                if (textContentFile.FileName.Equals(request.CatalogId) || textContentFile.FileName.Equals(request.CatalogNameg))
                {
                    //当前文本内容文件的HTML
                    htmlContent = textContentFile.Content;
                    break;
                }
                i++;
            }
            return htmlContent;
        }
        /// <summary>
        /// C#去除HTML标签
        /// </summary>
        /// <param name="html">带有html标签的文本</param>
        /// <param name="length">截取长度</param>
        /// <returns></returns>
        public string ReplaceHtmlTag(string html, int length = 0)
        {
            string strText = System.Text.RegularExpressions.Regex.Replace(html, "<[^>]+>", "");
            strText = System.Text.RegularExpressions.Regex.Replace(strText, "&[^;]+;", "");

            if (length > 0 && strText.Length > length)
                return strText.Substring(0, length);

            return strText;
        }
    }
}