.netcore mongodb 分页+模糊查询+多条件查询

.netcore MongoDB.Driver 版本才2.8 与aspnet差距太大，网上找很多资料没有现成的代码。

        public override async Task<PagerList<NewsContentDto>> PagerQueryAsync(NewsContentQuery parameter)
        {
            FilterDefinitionBuilder<NewsContentDto> builder = Builders<NewsContentDto>.Filter;
            string p = parameter.Keyword == null? $".*{Regex.Escape("")}.*": $".*{Regex.Escape(parameter.Keyword)}.*";
            FilterDefinition <NewsContentDto> filter2 = builder.Regex("title", new BsonRegularExpression(new Regex(p, RegexOptions.IgnoreCase)));
            //var filter1 = Builders<T>.Filter.Regex("title", new BsonRegularExpression(new Regex(".*" + Regex.Escape("英超") + ".*", RegexOptions.IgnoreCase)));
            //var filter1 = Filter.Regex(x => x.EnglishName, new MongoDB.Bson.BsonRegularExpression(parameter.Keyword, "i"));
            //BsonDocument filter = new BsonDocument {{"title", $"/{parameter.Keyword}/" } };
            //if(parameter.classifyId>0) filter.Add("classifyId", parameter.classifyId);
            
            var query = new QueryMongoParameter<NewsContentDto>(parameter, "news_content", filter2);
            var ret = await MongoContext.PagerQueryAsync(query);
            return ret;
        }

 分页查询

        public async Task<PagerList<T>> PagerQueryAsync<T>(QueryMongoParameter<T> query)
        {
            var skip = (query.Page - 1) * query.PageSize;
            var collection = _database.GetCollection<T>(query.CollectName);
            var data = await collection.Find(query.Filter).Sort(query.Sort).Project(query.Projection).Skip(skip).Limit(query.PageSize).ToListAsync();
            var total = await collection.CountAsync(query.Filter);
            var ret = new List<T>();
            data.ForEach(d =>
            {
                string s = d.ToString().Replace(""_id"", ""id"");
                ret.Add(Helpers.Json.ToObject<T>(s));
            });
            return new PagerList<T>(query.Page, query.PageSize, (int)total, ret);
        }

补充

    public class PageMongoParameter : ParameterBase
    {
        public BsonDocument Sort { get; }
        public BsonDocument Skip { get; }
        public BsonDocument Limit { get;}        
        public BsonDocument Filter2 { get; }

        public BsonDocument[] Pipeline { get; set; }
        public PageMongoParameter(PageRequest req, string collectName, BsonDocument filter=null,BsonDocument sort=null, BsonDocument filter2 = null)
        {
            CollectName = collectName;
            Page = req.pageindex;
            PageSize = req.pagesize;
            Limit = new BsonDocument { { "$limit", PageSize } };
            Skip = new BsonDocument { { "$skip", (Page-1)*PageSize} };

            if (sort == null)
            {
                if (!string.IsNullOrEmpty(req.order)) Sort = new BsonDocument { { "$sort", new BsonDocument { { req.order, 1 } } } };
            }
            else
            {
                Sort = sort;
            }

            if (filter != null && filter2==null)
            {
                var dom = filter.GetElement(0);
                Filter2 = BsonDocument.Parse(dom.Value.ToJson());
            }
            Filter2 = Filter2 ?? new BsonDocument();

            if (filter == null && Sort == null)
                Pipeline = new[] {Skip, Limit};
            else
            {
                if(filter!=null && Sort != null)
                    Pipeline = new[] { filter,Skip, Limit,Sort };
                else
                    Pipeline = filter == null ? new[] {Skip, Limit, Sort} : new[] { filter,Skip, Limit};
            }
        }
        

    }