获取 Listbox 的所有值作为列表

Question

这应该很简单，但对我来说肯定不简单。我有两个列表框，一个绑定到数据表，另一个不绑定任何东西。用户可以从绑定的列表框中选择记录，并将它们添加到未绑定的列表框中。我想检索未绑定框的内容作为列表并将列表作为输入提供给另一个类，我正在努力从未绑定列表框中获取值。这是我的代码的样子：

    Dim selectedT = (From i In lbSelectedT.Items).ToList()

    For Each T In selectedT
        MsgBox(T.ToString)

    Next

    ' output is: System.Data.DataRowView

我做错了什么？

Answer 1

你的第二个列表框应该和第一个一样绑定。然后在循环遍历项目时将它们完全视为源数据。

以下绑定到 listOption 对象列表。当您单击 button2 时，它会遍历项目，将它们隐式转换为 listOption，然后访问数据。

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        options.Add(New listOption("test 1", 1))
        options.Add(New listOption("test 2", 2))
        options.Add(New listOption("test 3", 3))
        options.Add(New listOption("test 4", 4))

        ListBox1.DataSource = options


        ListBox1.DisplayMember = "name"
        ListBox1.ValueMember = "id"

        ListBox2.DisplayMember = "name"
        ListBox2.ValueMember = "id"

    End Sub

    Public Property options As New List(Of listOption)
    Public Class listOption
        Public Property name As String
        Public Property id As Integer

        Sub New(name As String, id As String)
            Me.name = name
            Me.id = id
        End Sub
    End Class

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If ListBox1.SelectedItem IsNot Nothing Then
            ListBox2.Items.Add(ListBox1.SelectedItem)
        End If
    End Sub


    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Dim selectedT = (From i In ListBox2.Items).ToList()

        For Each T As listOption In selectedT
            MsgBox(T.name.ToString)

        Next
    End Sub
End Class