Question

1.当我从列表框1中选择一个项目时，它会显示有关listbox2中项目的信息。但是，当我单击listbox1中的某个项目时，它会向我显示该信息，并在listbox2的末尾添加0。我如何摆脱0或我正在做什么导致这个？我认为它可能正在显示索引号。这是我的代码 -

If ListBox1.SelectedIndex = 2 Then ListBox2.Items.Add("60137" & ListBox2.Items.Add("60138"))

2.另外，当我在list1中选择不同的项目时，如何清除List2，以便它们不会同时填充list2？

Answer 1

*忽略这是一个可怕的设计......

变化：

If ListBox1.SelectedIndex = 2 Then ListBox2.Items.Add("60137" & ListBox2.Items.Add("60138"))

要：

If ListBox1.SelectedIndex = 2 Then 
    ListBox2.Items.Clear
    ListBox2.Items.Add("60137")
End If

这是另一种方法：

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim petA As New Pet
        petA.Name = "Puss in Boots"
        petA.Species = "Cat"
        ListBox1.Items.Add(petA)

        Dim petB As New Pet
        petB.Name = "Nemo"
        petB.Species = "Fish"
        ListBox1.Items.Add(petB)

        Dim petC As New Pet
        petC.Name = "Rango"
        petC.Species = "Lizard"
        ListBox1.Items.Add(petC)
    End Sub

    Private Sub ListBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListBox1.SelectedIndexChanged
        If ListBox1.SelectedIndex <> -1 Then
            Dim P As Pet = DirectCast(ListBox1.SelectedItem, Pet)
            Label1.Text = P.Species
        End If
    End Sub

End Class

Public Class Pet

    Public Name As String
    Public Species As String

    Public Overrides Function ToString() As String
        Return Name
    End Function

End Class

在Listbox1中选择项目时，0添加到listbox2显示

1 个答案: