Question

我有一个Content对象列表（我在下面定义）

List<Content> ContentList;

我正在尝试使用LINQ创建一个搜索此列表的方法。该方法将此列表作为参数获取，但它也获得一个Query对象，其定义如此

public class DomainQuery
{
  public List<string> PhrasesIncludeAny { get; set; }
  public List<string> PhrasesIncludeAll { get; set; }
  public List<string> PhrasesExcludeAll { get; set; }
  public DateTime CreatedAfter { get; set; }
  public DateTime CreatedBefore { get; set; }
}

内容对象定义为

public class Content
{
  public List<string> Summary{ get; set; }
  public DateTime CreatedDate { get; set; }
}

linq语句需要遍历每个Content对象，并只选择与查询匹配的对象。短语的搜索位于“摘要”字段中。例如，摘要必须包括PhrasesIncludeAll列表中的所有短语（蓝色，红色贪婪），任何短语：sky，land，car（PhrasesIncludeAny），但不包括：Canada，US，UK。

Answer 1

假设我理解你想让你的操作员做什么，应该看起来像这样：

void Main()
{
    var queryInfo = new DomainQuery();
    var ContentList = new List<Content>();

    var query = ContentList
        .Where(q=>queryInfo.PhrasesIncludeAny
            .Any(item=>q.Summary.Any(subitem=>subitem == item)))
        .Where(q=>queryInfo.PhrasesIncludeAll
            .All(item=>q.Summary.All(subitem=>subitem == item)))
        .Where(q=>!queryInfo.PhrasesIncludeAll
            .All(item=>q.Summary.All(subitem=>subitem == item)))
        .Where(q=>q.CreatedDate < queryInfo.CreatedBefore)
        .Where(q=>q.CreatedDate > queryInfo.CreatedAfter);

}

Answer 2

你也可以试试这个

List<Content> ContentList = new List<Content>() 
                        { new Content { CreatedDate = DateTime.Now, Summary = new List<string>() { "America", "Pakistan", "India", "England" } }, 
                          new  Content { CreatedDate = DateTime.Now, Summary = new List<string>() { "Germany", "Holland", "Aus", "NewZealand" } }};

DomainQuery domainQuery = new DomainQuery { CreatedAfter = DateTime.Now.AddDays(-4), PhrasesExcludeAll = new List<string>() { "Aus" }, CreatedBefore = DateTime.Now, PhrasesIncludeAll = new List<string>() { "America", "Pakistan", "India", "England" }, PhrasesIncludeAny = new List<string>() { "India" } };

var result = ContentList.Where(c => domainQuery.PhrasesIncludeAny
                        .Any(item => c.Summary.Any(subItem => subItem == item))
           && !domainQuery.PhrasesExcludeAll.Any(item => c.Summary.Any(subItem => subItem == item))
           && !c.Summary.Except(domainQuery.PhrasesIncludeAll).Any()
           && c.CreatedDate < domainQuery.CreatedBefore
           && c.CreatedDate > domainQuery.CreatedAfter);



        foreach (var res in result)
        {
            res.Summary.ForEach(r => {
                    Console.WriteLine(r);
                });

        }
        Console.ReadKey();

高级搜索与LINQ一样

2 个答案: