按LINQ C#出现单词对列表进行排序
我已将数据存储在列表中
List list = new List(); SearchResult sr = new SearchResult(); sr.Description = "sample description"; list.Add(sr);
假设我的数据存储在描述字段中
"JCB Excavator - ECU P/N: 728/35700" "Geo Prism 1995 - ABS #16213899" "Geo Prism 1995 - ABS #16213899" "Geo Prism 1995 - ABS #16213899" "Wie man BBA reman erreicht" "this test JCB" "Ersatz Airbags, Gurtstrammer und Auto Körper Teile"
现在我想用我的搜索词查询列表,如geo jcb
如果你看,那么geo这个词在描述字段中存储了很多次。 所以我想以这样的方式对我的列表进行排序,使搜索词中的单词最大化,数据将首先出现。 请帮我这样做。 谢谢
您可以使用简单的正则表达式,只需将模式中的搜索项与|
:
var re = new Regex("geo|JCB",RegexOptions.IgnoreCase);
然后计算描述中的匹配数:
Console.WriteLine(re.Matches(description).Count); // Outputs '5' in your example
您可以通过以下方式订购列表:
searchResults.OrderByDescending(r => re.Matches(r).Count);
实例: http : //rextester.com/MMAT58077
编辑 :根据您在评论中链接的新问题(并希望您将更新此问题的详细信息并让复制品死亡)您希望订购结果,以便最常见的结果显示在结果列表的前面。
为此,您可以先计算每个搜索短语的相关权重,然后使用它来对结果进行排序。
步骤1:通过计算每个搜索词在整个数据集中出现的总次数来计算权重:
var wordsToFind = "Geo JCB".Split(); // find number of times each search phrase is found var weights = wordsToFind.Select( w => new { Word = w, Weight = list.Where(x => x.Description.Contains(w)).Count() } );
对于此问题中的数据,此时可以得出结果:
GEO: 3 JCB: 2
所以你首先想要所有的GEO
结果,然后是JCB
。 我想一个好的方法是让第一个结果成为最常提到GEO
结果。
步骤2:使用步骤1中计算的权重来排序搜索结果。
var values = list.Select(x => new { SearchResult = x, Words = x.Description.Split(' ') }) .Select(x => new { SearchResult = x.SearchResult, Weight = weights.Sum(w => x.Words.Contains(w.Word) ? w.Weight : 0) }) .OrderByDescending(x => x.Weight) .Select(x => x.SearchResult);
实例: http : //rextester.com/SLH38676
您可以将string.Split
和Enumerable.OrderByDescending
与匿名类型一起使用:
List list = new List () { new SearchResult(){Description="JCB Excavator - ECU P/N: 728/35700"}, new SearchResult(){Description="Geo Prism 1995 - ABS #16213899"}, new SearchResult(){Description="Geo Prism 1995 - ABS #16213899"}, new SearchResult(){Description="Geo Prism 1995 - ABS #16213899"}, new SearchResult(){Description="Wie man BBA reman erreicht"}, new SearchResult(){Description="this test JCB"}, new SearchResult(){Description="Ersatz Airbags, Gurtstrammer und Auto Körper Teile"}, }; string[] searchTerms = new[]{"geo", "jcb"}; var results = list.Select(sr => new { Searchresult = sr, Words = sr.Description.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries) }) .OrderByDescending(x => x.Words.Count(w => searchTerms.Contains(w.ToLower()))) .Select(x => x.Searchresult);
List list = new List () { new SearchResult { Description = "JCB Excavator - ECU P/N: 728/35700" }, new SearchResult { Description = "Geo Prism 1995 - ABS #16213899" }, new SearchResult { Description = "Geo Prism 1995 - ABS #16213899" }, new SearchResult { Description = "Geo Prism 1995 - ABS #16213899" }, new SearchResult { Description = "Wie man BBA reman erreicht" }, new SearchResult { Description = "this test JCB" }, new SearchResult { Description = "Ersatz Airbags, Gurtstrammer und Auto Körper Teile" } }; var wordsToFind = "Geo JCB".Split(); var values = list.Select(x => new { SearchResult = x, Count = x.Description.Split(' ') .Where(c => wordsToFind .Contains(c)).Count() }) .OrderByDescending(x => x.Count) .Select(x => x.SearchResult);
var results = db.Blogs.AsEnumerable() .Select(sr => new { Searchresult = sr, Words = Regex.Split(sr.Name, @"[^\S\r\n {1,}").Union(Regex.Split(sr.Name2, @"[^\S\r\n]{1,}")) }) .OrderByDescending(x => x.Words.Count(w => { foreach (var item in searchTerms) { if(w.ToLower().Contains(item)) { return true; } } return false; })) .Select(x => x.Searchresult);