C# と VB.NET の質問掲示板

■No74348 (モモ さん) に返信

以下のコードでどうでしょう？

Public Class Form1

    Private tbl As DataTable

    Public Sub New()
        ' この呼び出しはデザイナーで必要です。
        InitializeComponent()

        ' InitializeComponent() 呼び出しの後で初期化を追加します。
        tbl = New DataTable
        With tbl.Columns
            .Add("val")
            .Add("col1")
            .Add("col2")
        End With
        tbl.Rows.Add("01", "abc", "あいう")
        tbl.Rows.Add("02", "cde", "かきく")
        tbl.Rows.Add("03", "fgh", "さしす")
        ComboBox1.ValueMember = "val"
        ComboBox1.DisplayMember = "col1"
        ComboBox1.DataSource = tbl
    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        ComboBox1.DisplayMember = "col1"
        Label1.Text = ComboBox1.Text
    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        ComboBox1.DisplayMember = "col2"
        Label1.Text = ComboBox1.Text
    End Sub
End Class