[英]Sort List by occurrence of a word by LINQ C#
我已将数据存储在列表中
List<SearchResult> list = new List<SearchResult>();
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
您可以将string.Split
和Enumerable.OrderByDescending
与匿名类型一起使用:
List<SearchResult> list = new List<SearchResult>() {
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);
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副本死亡)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
因此,您首先需要所有GEO
结果,然后是JCB
。 我想一个不错的选择就是让第一个结果成为GEO
最常被提及的结果。
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
List<SearchResult> list = new List<SearchResult>()
{
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);
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