方法 : 項目のリストを作成する
更新 : 2007 年 11 月
このトピックのコードでは、Student クラスを定義し、クラスのインスタンスのリストを作成します。このリストは、トピック「チュートリアル : Visual Basic でのクエリの作成」をサポートするように設計されています。これは、オブジェクトのリストを必要とする任意のアプリケーションにも使用できます。このコードでは、オブジェクト初期化子を使用することで、学生のリスト内の各項目を定義します。
使用例
チュートリアルを実行している場合は、そのチュートリアルで作成するプロジェクトの Module1.vb ファイルとして、このコードを使用できます。Main メソッドの **** でマークされた行を、チュートリアルで指定されたクエリとクエリ実行に置き換えます。
Module Module1
Sub Main()
' Create a list of students.
Dim students = GetStudents()
' Display the names in the list.
DisplayList(students)
' ****Paste query and query execution code from the walkthrough,
' ****or any code of your own, here in Main.
Console.ReadLine()
End Sub
' Call DisplayList to see the names of the students in the list.
' You can expand this method to see other student properties.
Sub DisplayList(ByVal studentCol As IEnumerable(Of Student))
For Each st As Student In studentCol
Console.WriteLine("First Name: " & st.First)
Console.WriteLine(" Last Name: " & st.Last)
Console.WriteLine()
Next
End Sub
' Function GetStudents returns a list of Student objects.
Function GetStudents() As IEnumerable(Of Student)
Dim studentList As New System.Collections.Generic.List(Of Student)
Dim student0 As New Student With {.First = "Michael", _
.Last = "Tucker", _
.Year = "Junior", _
.Rank = 10}
Dim student1 As New Student With {.First = "Svetlana", _
.Last = "Omelchenko", _
.Year = "Senior", _
.Rank = 2}
Dim student2 As New Student With {.First = "Michiko", _
.Last = "Osada", _
.Year = "Senior", _
.Rank = 7}
Dim student3 As New Student With {.First = "Sven", _
.Last = "Mortensen", _
.Year = "Freshman", _
.Rank = 53}
Dim student4 As New Student With {.First = "Hugo", _
.Last = "Garcia", _
.Year = "Junior", _
.Rank = 16}
Dim student5 As New Student With {.First = "Cesar", _
.Last = "Garcia", _
.Year = "Freshman", _
.Rank = 4}
Dim student6 As New Student With {.First = "Fadi", _
.Last = "Fakhouri", _
.Year = "Senior", _
.Rank = 72}
Dim student7 As New Student With {.First = "Hanying", _
.Last = "Feng", _
.Year = "Senior", _
.Rank = 11}
Dim student8 As New Student With {.First = "Debra", _
.Last = "Garcia", _
.Year = "Junior", _
.Rank = 41}
Dim student9 As New Student With {.First = "Lance", _
.Last = "Tucker", _
.Year = "Junior", _
.Rank = 60}
Dim student10 As New Student With {.First = "Terry", _
.Last = "Adams", _
.Year = "Senior", _
.Rank = 6}
studentList.Add(student0)
studentList.Add(student1)
studentList.Add(student2)
studentList.Add(student3)
studentList.Add(student4)
studentList.Add(student5)
studentList.Add(student6)
studentList.Add(student7)
studentList.Add(student8)
studentList.Add(student9)
studentList.Add(student10)
Return studentList
End Function
' Each student has a first name, a last name, a class year, and
' a rank that indicates academic ranking in the student body.
Public Class Student
Private _first As String
Public Property First() As String
Get
Return _first
End Get
Set(ByVal value As String)
_first = value
End Set
End Property
Private _last As String
Public Property Last() As String
Get
Return _last
End Get
Set(ByVal value As String)
_last = value
End Set
End Property
Private _year As String
Public Property Year() As String
Get
Return _year
End Get
Set(ByVal value As String)
_year = value
End Set
End Property
Private _rank As Integer
Public Property Rank() As Integer
Get
Return _rank
End Get
Set(ByVal value As Integer)
_rank = value
End Set
End Property
End Class
End Module
参照
処理手順
チュートリアル : Visual Basic でのクエリの作成