VB 单选按钮和组合框 Flash

Question

我编写了一小段代码来在选择单选按钮时更改组合框的显示成员。我遇到的唯一问题是，当我在单选按钮之间切换时，组合框会消失，然后一秒钟后又回来，有没有办法解决这个问题。

Private Sub SearchOptionChange(sender As Object, e As EventArgs) Handles RBExchange.CheckedChanged, RBPostcode.CheckedChanged

    Dim RB As RadioButton = CType(sender, RadioButton)
    If RB.Name = "RBExchange" AndAlso RB.Checked Then
        ComboBox1.DisplayMember = "Exchange"
        ComboBox1.Text = ""

    ElseIf RB.Name = "RBPostcode" AndAlso RB.Checked Then
        ComboBox1.DisplayMember = "Postcode"
        ComboBox1.Text = ""

    End If


End Sub

Answer 1

我使用以下方法重现了您的问题，并且仅在 DropDownStyle 设置为 Simple 时才会发生。因此，如果可能，请将 DropDownStyle 设置为 DropDown。

注意我使用了 5,000 个项目并且没有闪烁，跳到 10,000 个并且闪烁在那里，所以除了上面的建议之外，如果可能的话，如果业务逻辑允许，请考虑减少 ComboBox 中的项目数。

使用测试并注意，当 DropDownStyle 设置为 Simple 时，即使 SuspendLayout 和 ResumeLayout 也无济于事。

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) _
        Handles MyBase.Load

        Dim ItemList As New List(Of item)

        For x As Integer = 0 To 50000

            ItemList.Add(New item With
                         {
                             .Exchange = "E" & x.ToString,
                             .PostCode = "P" & x.ToString
                         })
        Next

        ComboBox1.DisplayMember = "Exchange"
        ComboBox1.DataSource = ItemList

    End Sub
    Private Sub RBExchange_CheckedChanged(sender As Object, e As EventArgs) _
        Handles RBExchange.CheckedChanged, RBPostcode.CheckedChanged

        Dim RB As RadioButton = CType(sender, RadioButton)
        RB.SuspendLayout()
        If RB.Name = "RBExchange" AndAlso RB.Checked Then
            ComboBox1.DisplayMember = "Exchange"
            ComboBox1.Text = ""

        ElseIf RB.Name = "RBPostcode" AndAlso RB.Checked Then
            ComboBox1.DisplayMember = "Postcode"
            ComboBox1.Text = ""
        End If
        RB.ResumeLayout()
    End Sub
End Class
Public Class item
    Public Property Exchange
    Public Property PostCode
End Class