主题：ComboList 代码生成

老师下列代码没有生成 ComboList 能帮忙看下 ，我哪里写的不对

Dim str As String = ""
For Each dt As DataTable In DataTables
    str &= dt.Name & "|"
Next
If e.IsFocusCell Then
    If e.Col.Name = "加载范围" Then
        Dim dr As DataRow
        dr("加载范围").ComboList = dr( str )
        MessageBox.Show(str)
    End If
End If