Question

如何通过linq数据的每一行中出现的单词对列表进行排序？我从这里得到了一个给出正确输出的人的答案。这是代码：

void Main()
{
    List<SearchResult> list = new List<SearchResult>() { 
        new SearchResult(){ID=1,Title="Geo Prism GEO 1995 GEO* - ABS #16213899"},
        new SearchResult(){ID=2,Title="Excavator JCB - ECU P/N: 728/35700"},
        new SearchResult(){ID=3,Title="Geo Prism GEO 1995 - ABS #16213899"},
        new SearchResult(){ID=4,Title="JCB Excavator JCB- ECU P/N: 728/35700"},
        new SearchResult(){ID=5,Title="Geo Prism GEO,GEO 1995 - ABS #16213899 GEO"},
        new SearchResult(){ID=6,Title="dog"},
    };

    var to_search = new[] { "Geo", "JCB" };

    var result = from searchResult in list
         let key_string = to_search.FirstOrDefault(ts =>  searchResult.Title.ToLower().Contains(ts.ToLower()))
         group searchResult by key_string into Group
         orderby Group.Count() descending
         select Group;
         result.ToList().Dump();



 }
// Define other methods and classes here
public class SearchResult
{
    public int ID { get; set; }
    public string Title { get; set; }
}

我得到了像

这样的输出

ID Title 
-- ------
1  Geo Prism GEO 1995 GEO* - ABS #16213899 
3  Geo Prism GEO 1995 - ABS #16213899 
5  Geo Prism GEO,GEO 1995 - ABS #16213899 GEO 
2  Excavator JCB - ECU P/N: 728/35700 
4  JCB Excavator JCB- ECU P/N: 728/35700 
6  dog

以上输出没问题。具有ord GEO的所有行首先出现，因为它在大多数行中找到最大时间意味着GEO在3行中找到该字，而JCB在两行中找到，因此接下来是JCB相关行。

在获得整个数据的上述输出后，我需要另一种排序。那就是GEO行首先出现哪一行具有GEO字最大时间。所以我的输出如下所示：

ID Title 
-- ------
5  Geo Prism GEO,GEO 1995 - ABS #16213899 GEO 
1  Geo Prism GEO 1995 GEO* - ABS #16213899 
3  Geo Prism GEO 1995 - ABS #16213899 
4  JCB Excavator JCB- ECU P/N: 728/35700 
2  Excavator JCB - ECU P/N: 728/35700 
6  dog

我找到了一个linq查询，用于计算字符串中单词的出现次数：

string text = @"Historically, the world of data and data the world of objects data" ;
string searchTerm = "data";
//Convert the string into an array of words
string[] source = text.Split(new char[] { '.', '?', '!', ' ', ';', ':', ',' },   StringSplitOptions.RemoveEmptyEntries);
var matchQuery = from word in source
             where word.ToLowerInvariant() == searchTerm.ToLowerInvariant()
             select word;
int wordCount = matchQuery.Count();

我是从this url

得到的

我如何使用上面的代码对我的标题进行排序？如何使用第二种排序来计算标题字段中单词的出现次数，结果我的输出看起来像：

ID Title 
-- ------
5  Geo Prism GEO,GEO 1995 - ABS #16213899 GEO 
1  Geo Prism GEO 1995 GEO* - ABS #16213899 
3  Geo Prism GEO 1995 - ABS #16213899 
4  JCB Excavator JCB- ECU P/N: 728/35700 
2  Excavator JCB - ECU P/N: 728/35700 
6  dog

Answer 1

使用WordCount作为字符串的扩展方法，然后可以使用简单的Lambda表达式：

list.OrderByDescending(sR => sR.Title.WordCount( to_search ))

如果您想省略所有没有搜索字词的结果，可以使用Where子句。即。

IEnumerable<SearchResult> results = list
                .Where( sR => sR.Title.WordCount( searchTerms ) > 0 )
                .OrderByDescending( sR => sR.Title.WordCount( searchTerms ) );

修改如果搜索条件对它们有优先权，您可以对每个项目进行多种排序（首先按最低优先级元素排序，然后是下一个，直到最终排序位于具有最高优先级的项目上）：

string[] searchTerms = new string[]{ "GEO","JCB" }; IEnumerable<SearchResult> results = list; foreach( string s in searchTerms.Reverse() ) { results = results .OrderByDescending( sR => sR.Title.WordCount( s ) ); }

扩展方法：

static class StringExtension{ public static int WordCount( this String text, string searchTerm ) { string[] source = text.Split( new char[] { '.', '?', '!', ' ', ';', ':', ',' }, StringSplitOptions.RemoveEmptyEntries ); var matchQuery = from word in source where word.ToLowerInvariant() == searchTerm.ToLowerInvariant() select word; int wordCount = matchQuery.Count(); return wordCount; } public static int WordCount( this String text, IEnumerable<string> searchTerms ) { int wordCount = 0; foreach( string searchTerm in searchTerms ) { wordCount += text.WordCount( searchTerm ); } return wordCount; } }

Answer 2

这个怎么样：

IEnumerable<SearchResult> result =
    from searchResult in list
    let key_string = to_search.FirstOrDefault(ts => searchResult.Title.ToLower().Contains(ts.ToLower()))
    group searchResult by key_string into Group
    orderby Group.Count() descending
    from item in Group.OrderByDescending(theItem => WordCount(theItem.Title, Group.Key))
    select item;

使用以下WordCount方法：

public static int WordCount( String text, string searchTerm )
{
    string[] source = text.Split( new char[] { '.', '?', '!', ' ', ';', ':', ',' }, StringSplitOptions.RemoveEmptyEntries );
    var matchQuery = from word in source
                     where word.ToLowerInvariant() == searchTerm.ToLowerInvariant()
                     select word;
    int wordCount = matchQuery.Count();
    return wordCount;
}

我注意到的一个小问题是，不包含匹配单词的标题将被组合在一起，因此可以将它们放在具有匹配单词的标题前面。

Answer 3

这一行之后：

var result = from searchResult in list
         let key_string = to_search.FirstOrDefault(ts =>  searchResult.Title.ToLower().Contains(ts.ToLower()))
         group searchResult by key_string into Group
         orderby Group.Count() descending
         select Group;

你想要这样的东西：

foreach (var group in result) {
      foreach (var item in group.OrderByDescending(theItem => WordCount(theItem.Title, group.Key))) {
          Console.WriteLine(item.Title);
      }
}

添加的方法如下：

public static int WordCount(string haystack, string needle) {
    if (needle == null) {
        return 0;
    }
    string[] source = haystack.Split(new char[] { '.', '?', '!', ' ', ';', ':', ',' }, StringSplitOptions.RemoveEmptyEntries);
    var matchQuery = from word in source
                        where word.ToLowerInvariant() == needle.ToLowerInvariant()
                        select word;
    return matchQuery.Count();
}

按列表行linq中的Word的计数出现次数排序

3 个答案: