(startFolder); var fileList = dir.GetFiles("*.*", SearchOption.AllDirectories); string searchTerm = "change"; var queryMatchingFiles = from file in fileList where file.Extension == ".txt" let fileText = File.ReadAllText(file.FullName) where fileText.Contains(searchTerm) select ...
I'd say the Intersect method (see answer by dasblinkenlight) + Any must work better than Contains + Any. It is definetely better to use Any than Count. 参考:https://stackoverflow.com/questions/13715529/check-whether-a-liststring-contains-an-element-in-another-liststring-using-l...
Linq Contains操作符在评估序列中是否包括您所查找的项目时类似于Any操作符。Any操作符可确定序列的某个项中是否存在某个值,而Linq Contains操作符则确定序列中是否存在特定项目实例。例如,在将某个对象添加到序列中之前,您可能希望确保序列中并未包含该对象。 复制 using (Entitiesentities=newEntities()){Customerscus...
var q = (from o in db.Orders where (new string[] { "AROUT", "BOLID", "FISSA" }).Contains(o.CustomerID) select o).ToList(); Not Contains则取反: var q = (from o in db.Orders where !(new string[] { "AROUT", "BOLID", "FISSA" }).Contains(o.CustomerID) select o).ToList...
问LINQ .Contains在列表上EN在 dotnet 可以使用 Take 获取指定数量的元素，获取顺序是从前向后，而获取...
publicstaticIEnumerable<XElement>FindAllElementsWithAttribute(XElement documentRoot,stringelementName,stringattributeName,stringvalue){returnfromelindocumentRoot.Elements(elementName)where(string)el.Element(attributeName) ==valueselectel; } 编写代码以手动遍历 XML 文档以执行此任务将更具挑战性。
AnyBoolean✓ AsEnumerableIEnumerable<T>✓ Average單一數值✓ CastIEnumerable<T>✓ ConcatIEnumerable<T>✓ ContainsBoolean✓ CountInt32✓ DefaultIfEmptyIEnumerable<T>✓ DistinctIEnumerable<T>✓ ElementAtTSource✓ ElementAtOrDefaultTSource?✓ ...
IEnumerable<string> query = from s in names where s.Length == 5 orderby s select s.ToUpper(); ローカル変数クエリはクエリ式で初期化されます。 クエリ式は、標準クエリ演算子またはドメイン固有の演算子から 1 つ以上のクエリ演算子を適用することで、1 つ以上の情報ソースに対して...
无法翻译LINQ表达式DbSet<>.Any 、、、 throw new ConflictException($"Call already exists");运行后,得到以下异常 System.InvalidOperationException:LINQ表达式“DbSet.Any(c => c.Number == __request_Number_0 & c.CustomerId == __request_CustomerId_1)”无法翻译。要么用可以翻译的表单重写查询,要么通...
下面的代码示例演示如何使用 Any<TSource>(IQueryable<TSource>) 来确定序列是否包含任何元素。 C# 复制 运行 List<int> numbers = new List<int> { 1, 2 }; // Determine if the list contains any elements. bool hasElements = numbers.AsQueryable().Any(); Console.WriteLine("The list {0} empty...