本主題中的程式代碼會定義 類別 Student ,並建立 類別的實例清單。 此清單旨在支援主題逐步指引:如何在 Visual Basic 中撰寫查詢。 它也可用於任何需要物件清單的應用程式。 程式碼會使用物件初始化器來定義學生列表中的項目。
範例
如果您正在進行逐步解說,您可以針對在該處建立之專案的Module1.vb檔案使用此程序代碼。 只要將 Main 方法中標示為 **** 的行替換成逐步解說中提供的查詢和查詢執行。
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)
Return New List(Of Student) From
{
New Student("Michael", "Tucker", "Junior", 10),
New Student("Svetlana", "Omelchenko", "Senior", 2),
New Student("Michiko", "Osada", "Senior", 7),
New Student("Sven", "Mortensen", "Freshman", 53),
New Student("Hugo", "Garcia", "Junior", 16),
New Student("Cesar", "Garcia", "Freshman", 4),
New Student("Fadi", "Fakhouri", "Senior", 72),
New Student("Hanying", "Feng", "Senior", 11),
New Student("Debra", "Garcia", "Junior", 41),
New Student("Lance", "Tucker", "Junior", 60),
New Student("Terry", "Adams", "Senior", 6)
}
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
Public Property First As String
Public Property Last As String
Public Property Year As String
Public Property Rank As Integer
Public Sub New()
End Sub
Public Sub New(ByVal firstName As String,
ByVal lastName As String,
ByVal studentYear As String,
ByVal studentRank As Integer)
First = firstName
Last = lastName
Year = studentYear
Rank = studentRank
End Sub
End Class
End Module