Como: Criar uma lista de itens
O código neste tópico define um Student classe e cria uma lista de instâncias da classe. A lista é projetada para suportar o tópico Demonstra Passo a passo: Escrever consultas no Visual Basic. Ele também pode ser usado para qualquer aplicativo que requer uma lista de objetos.O código define os itens na lista de alunos usando os inicializadores de objeto.
Exemplo
Se você estiver trabalhando na explicação passo a passo, você pode usar este código para o arquivo Module1.vb do projeto criado lá.Substituir apenas as linhas marcadas com **** no Main método com as consultas e execuções de consulta fornecidas nesta explicação passo a passo.
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
Consulte também
Tarefas
Demonstra Passo a passo: Escrever consultas no Visual Basic
Conceitos
Inicializadores de objeto: Tipos nomeados e anônimos
Introdução ao LINQ no Visual Basic