主题：分隔符的问题

请教老师，下面代码，生成的“指定质量评价人”的时候怎样让分隔符自动调整，不出现空值，因为表A的三列是随机填入内容的

 

例子        

                   表A                                     表B                               表B应该实现

       校对      审核      批准                   指定质量评价人

                   老李     老张                    ，老李，老张                        老李，老张

       老马                 老张                    老马，，老张                        老马，老张

       老马       老李                              老马，老李，                        老马，老李

       老马       老李     老张                   老马，老李，老张                   老马，老李，老张

 

If e.DataCol.Name = "校对" OrElse e.DataCol.Name = "审核" OrElse e.DataCol.Name = "批准" Then
   Dim pdr As DataRow = DataTables("表B").find("任务索引 = '" & e.DataRow("任务索引") & "'")
        If pdr IsNot Nothing Then
            Dim str As String = ""
            Dim str1 As String = ""
            Dim str2 As String = ""
            For Each drr As DataRow In DataTables("表A").Select("任务索引 = '" & e.DataRow("任务索引") & "'")
                str &  = drr("校对") & "," 
                str1 & = drr("审核") & "," 
                str2 & = drr("批准")  
            Next
            pdr("指定质量评价人") = (str & str1 & str2)'.trim(chr(13),chr(10))
    End If
End If