主题：排除字符串中的重复名字。

参考

Dim dt As DataTable = DataTables("表A")
Dim ls As new List(Of String)
For Each dr As DataRow In dt.Select("")
    For Each s As String In dr("第一列").split(",")
        If ls.Contains(s) = False Then
            ls.add(s)
        End If
    Next
Next
msgbox(String.join(",", ls.ToArray))