Question

我有以下代码，我需要获得与两个属性匹配的所有IndividualRef - 它需要使用AND而不是OR。例如，下面的代码应该只给我个人参考22，因为他匹配＆＃34; ST＆＃34;和＆＃34; BJOG＆＃34;

你知道LINQ语句会这样做吗？

string AttributeList = "ST,BJOG,";
        List<StratogIndividuals> inds = new List<StratogIndividuals>();
        StratogIndividuals s = new StratogIndividuals();
        string[] attributes = AttributeList.Split(',').Where(x => x != "").ToArray();

        s.AttributeCode = "ST";
        s.IndividualRef = "22";
        inds.Add(s);

        s = new StratogIndividuals();
        s.AttributeCode = "BJOG";
        s.IndividualRef = "22";
        inds.Add(s);

        s = new StratogIndividuals();
        s.AttributeCode = "BJOG";
        s.IndividualRef = "20";
        inds.Add(s);

        s = new StratogIndividuals();
        s.AttributeCode = "XXF";
        s.IndividualRef = "21";
        inds.Add(s);

当然，AttributeList的大小可以增加。感谢

Answer 1

使用列表或数组来保存您需要检查的所有属性。可以使用LINQ进行搜索 - 创建个人查找，通过ref返回所有单独的属性代码，然后检查组是否包含所有属性：

var attributes = new []{ "ST", "BJOG" };

var refs = inds.ToLookup(i => i.Ref, i => i.AttributeCode)
               .Where(g => !attributes.Except(g).Any())
               .Select(g => g.Key);

Answer 2

请试试这个。使用GroupBy IndividualRef 然后使用 SetEqual 将其与属性匹配。

List<StratogIndividuals> inds = new List<StratogIndividuals>(){
            new StratogIndividuals(){ AttributeCode = "ST", IndividualRef = "22"},
            new StratogIndividuals(){ AttributeCode = "BJOG", IndividualRef = "22"},
            new StratogIndividuals(){ AttributeCode = "BJOG", IndividualRef = "20"},
            new StratogIndividuals(){ AttributeCode = "XXF", IndividualRef = "21"},
        };

        string AttributeList = "ST,BJOG,";
        string[] attributes = AttributeList.Split(',').Where(x => x != "").ToArray();

        var results = inds.GroupBy(ind => ind.IndividualRef)
            .Where(g => new HashSet<string>(g.Select(i => i.AttributeCode)).SetEquals(attributes))
            .Select(x => x.Key).ToList();

使用c＃LINQ从列表中获取与BOTH属性匹配的值

2 个答案: