Question

我有一个图像列表，我想搜索具有两个规则的多个关键字

例如，如果我搜索跳舞的孩子＆＃34;我想显示一个包含关键字dance和child

的项目列表

我实现了类似这样的查询：

List<string> target_keywords = //an array contains Keywords to Lookup 
var RuleAny_results = (from imageItem in images                     
                       select new{ imageItem,
                             Rank =target_keywords.Any(x => imageItem.Title != null && imageItem.Title.ToLower().Contains(x)) ? 5 :
                                   target_keywords.Any(x => imageItem.Name != null && imageItem.Name.ToLower().Contains(x)) ? 4 :                                  
                                0
                         }).OrderByDescending(i => i.Rank);
//exclude results with no match (ie rank=0 ) and get a Distinct set  of items
_searchResult = (from item in RuleAny_results
             where item.Rank != 0
             select item.imageItem).Distinct().ToList();

但是这会返回target_keywords中任何项目的结果，例如如果我寻找跳舞的孩子＆＃34;上面的代码返回任何关键字舞蹈或儿童的项目列表。但我希望列表只包含舞蹈和儿童关键词

那么如何转换查询以便获取包含BOTH关键字的所有记录？

Answer 1

System.Linq.Enumerable :: All就是你想要的。

using System.Linq;
using System.Collections.Generic;

struct ImageItem {
    public string Title { get; set; }
    public string Name { get; set; }
}

bool Contains(string toSearch, string x) {
    return toSearch != null && toSearch.ToLower().Contains(x);
}

IEnumerable<ImageItem> FilterItems(IEnumerable<string> targetKeywords, IEnumerable<ImageItem> items) {
    return items.Where(item => targetKeywords.All(x => Contains(item.Name, x) || Contains(item.Title, x)));

}

Answer 2

试试这个： -

您必须在语法中用全部替换任何关键字还有两个字段中所有关键字的排名条件

将target_keywords.Any(替换为target_keywords.All(

List<string> target_keywords = //an array contains Keywords to Lookup 
var RuleAny_results = (from imageItem in images                     
                       select new{ imageItem,
                             Rank =target_keywords.Any(x => imageItem.Title != null && imageItem.Title.ToLower().Contains(x)) ? 5 :
                                   target_keywords.All(x => imageItem.Name != null && imageItem.Name.ToLower().Contains(x)) ? 4 :   
                                   target_keywords.All(x => (imageItem.Name != null && imageItem.Name.ToLower().Contains(x)) || imageItem.Title != null && imageItem.Title.ToLower().Contains(x)) ? 3 :                                
                                0
                         }).OrderByDescending(i => i.Rank);
//exclude results with no match (ie rank=0 ) and get a Distinct set  of items
_searchResult = (from item in RuleAny_results
             where item.Rank != 0
             select item.imageItem).Distinct().ToList();

Answer 3

class ImageDemo
    {
        public string Title { get; set; }
        public string Name { get; set; }
    }

    static void TestCode()
    {
        List<string> target_keywords = new List<string>(){"dancing","child"};
        List<ImageDemo> images = new List<ImageDemo>()
        {  
            new ImageDemo{Title = "dancing"}  ,
             new ImageDemo{Name = "child"}  ,
             new ImageDemo{Title = "child", Name="dancing"}  ,
             new ImageDemo{Title = "dancing", Name="child"}  ,
             new ImageDemo{Name="dancing child"} ,
             new ImageDemo{Title="dancing child"} 
        };
        var searchFuncs = target_keywords.Select(x =>
        {
            Func<ImageDemo, bool> func = (img) =>
            {
                return (img.Title ?? string.Empty).Contains(x) || (img.Name ?? string.Empty).Contains(x);
            };
            return func;
        });
        IEnumerable<ImageDemo> result = images;
        foreach (var func in searchFuncs)
        {
            result = result.Where(x => func(x));
        }
        foreach (var img in result)
        {
            Console.WriteLine(string.Format("Title:{0}  Name:{1}", img.Title, img.Name));
        }
    }

这是你现在想要的正确代码吗？

使用数组

3 个答案: