Dim tb As Table = Tables("配件计划")
Dim r As Row = Tb.current
If r IsNot Nothing Then
    If tb.GetCheckedRows.count = 0 Then
        messagebox.show("没有可用于生成 配件采购单 的数据信息!","提示")
        Return
    ElseIf tb.GetCheckedRows.count > 0 Then
        Dim Result As DialogResult
        Result = MessageBox.Show("是否要根据 ""计划需求数量"" 生成 配件采购单 ?", "提示",  MessageBoxButtons.YesNo, MessageBoxIcon.Question)
        If Result = DialogResult.Yes Then
           
            Dim dic As new Dictionary(of String, Row)
            For i As Integer = 0 To Tb.GetCheckedRows.count -1
                Dim r1 As Row = tb.GetCheckedRows(i)
                If dic.ContainsKey(r1("供应商编号")) = False
                    dic.add(r1("供应商编号"), Tables("配件采购主表").addnew())
                End If
                Dim r3 As Row = dic(r1("供应商编号"))
                r3("配件采购系统编号") = "PJCG-"
                r3("供应商名称") = r1("供应商名称")
                r3("供应商编号") = r1("供应商编号")
                r3("开单员") = user.name
                r3("开单日期") = Date.Today
               
               
                Dim r2 As Row = Tables("配件采购子表").addnew()
                Dim nms() As String = {"配件编号","配件名称","配件规格","货品单位","配件品牌","配件材质","货品类别","货品颜色"}
                r2("供应商编号") = r1("供应商编号")
                For Each nm As String In nms
                    r2(nm) = r1(nm)
                    r2("配件数量") = r1("计划需求数量")
                Next
            Next
            Forms("配件计划").close()
        End If
    End If
End If

如果有问题，尽量发实例上来测试。