varlist1 =newList<User>{newUser{UserID=1, Name ="User1",Sex="Male"},newUser{UserID=2, Name ="User2",Sex="Female"}, };varlist2 =newList<User>{newUser{ UserID=2, Name ="User2",Sex="Female"},newUser{ UserID=3, Name
Imports System.Collections Imports System.Linq Module Module1 Public Class Student Public Property FirstName As String Public Property LastName As String Public Property Scores As Integer() End Class Sub Main() Dim student1 As New Student With {.FirstName = "Svetlana", .Last...
BinaryExpression comparison=Expression.GreaterThan(property, constant);//构建 Lambda 表达式Expression<Func<Person,bool>> lambda = Expression.Lambda<Func<Person,bool>>(comparison, parameter);//编译表达式树并使用Func<Person,bool> func =lambda.Compile();//测试查询条件varpeople =new[] {newPerson { Nam...
List<T> 实现了 ICollection<T> 和 IEnumerable<T> 接口,它是一个动态数组,提供对元素的快速访问和操作。 publicclassList<T> : IList<T>, ICollection<T>, IEnumerable<T>, IEnumerable, IList, ICollection, IReadOnlyList<T>, IReadOnlyCollection<T>, IReadOnlyList, IReadOnlyCollection {// 具体实现}...
DimqueryResults =FromcustIncustomersWherecust.Country ="Canada" 另一个功能强大的查询子句是Select子句,它能够从数据源仅返回所选字段。 LINQ 查询返回强类型化对象的可枚举集合。 查询可以返回匿名类型或具名类型的集合。 可以使用Select子句从数据源仅返回单个字段。 执行此操作时,返回的集合类型为该单个字段的类型...
By default, the AutoPage property is true. If you assign a value to the Select property, you must also include all identity columns in the list of properties that is returned in the query. Grouping Data You use the GroupBy property to specify which properties are used to consolidate data ...
of the listDimfilesByLengDesc =FromfileInfileList _Letfilelength = GetFileLength(file) _Wherefilelength >0_OrderByfilelength Descending _SelectfileDimlongestFile = filesByLengDesc.First Console.WriteLine("The largest file under {0} is {1} with a length of...
publicstaticboolPublicInstancePropertiesEqual<T>(thisT self, T to,paramsstring[] ignore)whereT :class{if(self ==null|| to ==null) {returnself == to; }// Selects the properties which have unequal values into a sequence of those properties.varunequalProperties =frompropertyintypeof(T).GetPr...
By default, the AutoPage property is true. If you assign a value to the Select property, you must also include all identity columns in the list of properties that is returned in the query.Grouping DataYou use the GroupBy property to specify which properties are used to consolidate data ...
(fromfileinfileListletlen = GetFileLength(file)wherelen >0orderbylendescendingselectfile) .First(); Console.WriteLine("The largest file under {0} is {1} with a length of {2} bytes", startFolder, longestFile.FullName, longestFile.Length);//Return the FileInfo of the smallest fileSystem....