主题：一下子懵了

方法一：

For Each s As String In DataTables("表A").GetValues("第一列")
    Dim fdr As DataRow = DataTables("表A").Find("第一列 = '" & s & "'")
Next

方法二：

Dim ls As new List(Of String)
For Each dr As DataRow In DataTables("表A").Select("")
    If ls.Contains(dr("第一列")) = False Then
        ls.Add(dr("第一列"))
        msgbox(dr("第二列"))
    End If
Next