/// <summary>
/// 查看某篇文章内容
/// 2019/5/9
/// </summary>
/// <param name="articleID"></param>
/// <returns>文章信息</returns>
public async Task <ArticleDetailDto> GetArticleDetail(int articleID)
{
Article article = null;
//Id不能小于等于0
if (articleID <= 0)
{
_logger.LogError("传入文章Id格式错误：" + articleID);
return(null);
}
//将该文章Id和RedisArticle组合，作为Redis键名
string redisArticleKey = PostConsts.ArticleBaseKey + articleID;
//存入Redis缓存
//如果不存在，则执行查询数据库的操作
article = (Article)await _cacheManager.GetCache(PostConsts.RedisForArticleStore).GetAsync(redisArticleKey, async _ => await _articleRepository
.FirstOrDefaultAsync(s => s.Id == articleID));
//更新浏览量
article.PageView++;
await _cacheManager.GetCache(PostConsts.RedisForArticleStore).SetAsync(redisArticleKey, article);
//浏览量每上涨20，更新数据库
//可切换后台作业程序，一天同步一次数据
if (article.PageView % 7 == 0)
{
await _articleRepository.UpdateAsync(article);
}
if (article == null)
{
_logger.LogError("查看文章不存在，查看失败");
return(null);
}
//获取文章的路径并提取文件内容、标题等信息
//AutoMapper
var articleDetailDto = article.MapTo <ArticleDetailDto>();
//判断文件是否为txt文档
if (Path.GetExtension(article.ArticleUrl) != ".txt")
{
_logger.LogError("文章格式不支持，查看失败");
return(null);
}
string contentResult = await FileOperate.GetContentByPathAsync(article.ArticleUrl, _logger);
if (contentResult == "false")
{
_logger.LogError("从硬盘读取文章错误，查看失败");
return(null);
}
//在使用decodeURIComponent()函数时，所有的空格会变为加号，所以这里将加号变换为空格
contentResult = contentResult.Replace("+", " ");
articleDetailDto.Content = contentResult;
return(articleDetailDto);
}
