一.主模块代码: 'Fig.4.16:GradeBookTest.vb 'Create and manipulate a GradeBook object;illustrate validation Module GradeBookTest 'Main begins program execution Sub Main() 'creat GradeBook object Dim gradeBook1 As New GradeBook("CS101 Introduction to Visual B…
一.代码 ' Fig. 9.7: LINQWithListCollection.vb ' LINQ to Objects using a List(Of String). Module LINQWithListCollection Sub Main() ' populate a List of Strings Dim items As New List(Of String) items.Add("aqua") ' add "aqua" to the end of t…
一.模块代码 ' Fig. 9.4: LINQWithArrayOfObjects.vb ' LINQ to Objects using an array of Employee objects. Module LINQWithArrayOfObjects Sub Main() ' initialize array of employees Dim employees As Employee() = { _ New Employee("Jason", "Red",…
一.模块代码 ' Fig. 9.6: ListCollection.vb ' Generic List collection demonstration. Module ListCollection Sub Main() Dim items As New List(Of String) ' create a new List of Strings items.Add("red") ' append an item to the List items.Insert(0, "ye…
片段代码: ' Exercise 9.3 Solution: Invoice.vb ' Invoice class. Public Class invoide ' declare variables for Invoice object Private partNumberValue As Integer Private partDescriptionValue As String Private quantityValue As Integer Private priceValue As De…
一.主模块代码: 'Fig.4.13:GradeBookTest.vb 'GradeBook constructor used to specify the course name at the 'time each GradeBook object is created. Module GradeBookTest 'Main begins program execution Sub Main() 'creat GradeBook object Dim gradeBook1 As New Gra…
一.复习基础——属性与实例变量 'Fig. 4.8:GradeBookTest.vb 'Create and manipulate a GradeBook object. Module GradeBookTest 'Main begins program execution Sub Main() 'line 8 creates a GrateBook object that is referenced by 'variable gradeBook of type GradeBook Dim gr…
大家都知道Linq既可以用来查询数据库对象(我这里指的是Entity FrameWork里的Model对象),也可以用来查询内存中的IEnumerable对象. 两者单独查询时都不会出现什么问题,不过混合在一起时(一般是用关键字来join连接),要注意的地方就多着了. 情形1:Linq to Object 连接(join) Linq to Entity 我们首先来看这段代码:(注意:Linq代码里是把内存中的数据代码,也就是Linq to object放在join前面,数据库的数据代码放在joi…
建议19:使用更有效的对象和集合初始化 依赖于属性和FCL 3.5之后的语法规则,现在我们有了更加简洁有效的对象和集合初始化机制:对象和集合初始化设定项. 对象初始化: class Person { public string Name { get; set; } public int Age { get; set; } } class Program { static void Main(string[] args) { Person person = }; Console.Read(); }…
前一章的代码LINQ都是以select结尾. 之前也说过可以group结尾. 那么怎么使用呢? 还是一样的条件,查询小于5大于0的元素 代码: ,,,,,,,,, }; var list = from i in NumArray && i < group i by i; foreach (var item in list) foreach(var s in item) Console.Write($" {s}"); Console.ReadKey(); LINQ的…
此Demo只是一个极其简单的LINQ查询Demo 一个类 using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ConsoleApp1 { public class NBA_Star { public string FirstName { get; set; } public string LastN…
