public virtual void UpdateBlogPostTags(BlogPost blogPost, string[] blogPostTags)
{
if (blogPost == null)
{
throw new ArgumentNullException(nameof(blogPost));
}
var existingBlogPostTags = blogPost.BlogPostTags.ToList();
var blogPostTagsToRemove = new List <BlogPostTag>();
//筛选出需要删除的标签
foreach (var existingBlogPostTag in existingBlogPostTags)
{
var found = false;
foreach (var newProductTag in blogPostTags)
{
if (existingBlogPostTag.Name.Equals(newProductTag, StringComparison.InvariantCultureIgnoreCase))
{
found = true;
break;
}
}
if (!found)
{
blogPostTagsToRemove.Add(existingBlogPostTag);
}
}
//删除标签
foreach (var blogPostTag in blogPostTagsToRemove)
{
blogPost.BlogPostTags.Remove(blogPostTag);
_blogService.UpdateBlogPost(blogPost);
}
//新增标签
foreach (var tagName in blogPostTags)
{
BlogPostTag blogPostTag;
var blogPostTag2 = GetBlogPostTagByName(tagName);
if (blogPostTag2 == null)
{
blogPostTag = new BlogPostTag
{
Name = tagName
};
InsertBlogPostTag(blogPostTag);
}
else
{
blogPostTag = blogPostTag2;
}
if (!blogPost.BlogPostTagExists(blogPostTag.Id))
{
blogPost.BlogPostTags.Add(blogPostTag);
_blogService.UpdateBlogPost(blogPost);
}
}
}
