或者For Each dr As DataRow In DataTables("表A").DataRows
Dim lst As new List(of String) '用于储存目标内容
Dim ss As String = dr("物料编码")
For i As Integer = 1 To len(ss)
Dim fdr As DataRow = DataTables("表A").find("物料编码='" & left(ss,i) & "'")
lst.add(fdr("数量"))
Next
dr("数量辅助列") = Eval(String.join("*",lst.ToArray))
Next