标题：请教循环遍历结构问题

由于temptable表是在递归函数中动态增加记录的，所以不能用FOR each 遍历，会出现异常。

循环遍历temptable临时表,读取行记录后删除行，直到该表记录行为空，用以下格式遍历，应该怎么样写如下两个语句：

1.终止条件

2.下一条记录指令

do while  (终止条件【表中无记录时】）

    ’读取当前记录

    ’删除当前记录

    ’下一条记录指令

loop

For each dr dataRow in DataTables("xxx")

   '循环读取

next

DataTables("xxx").DataRows.Clear '全部删除

这样可以吗：

for i as integer = tables("临时表").count-1 to 0 step -1

    ..........

next

For Each r As DataRow In DataTables("tempbom").DataRows
    If r IsNot Nothing Then
    Dim dt1 As DataTable
    Dim cmd1 As New SQLCommand
    Dim curgoid As Integer
    curgoid = r("goid")
    r.Delete
    cmd1.CommandText = "Select goid,singletotal,comgoid,sf_nonstock From {cp_singlebom} Inner JOIN {product} ON {product}.[_Identify] = {cp_singlebom}.[goid]  where {cp_singlebom}.[goid]=" & CSTR(curgoid)
    dt1 = cmd1.ExecuteReader()
  
    If dt1.DataRows.Count > 0 Then
    '循环调用自身函数
   
    Else
       '追加到数据表中
        Dim r1 As Row = Tables("bomdata").AddNew()
        r1("goid") = curgoid
       ' r("singletotal")=dr("singletotal")
       ' r("sf_summy")= dr("sf_nonstock")
       ' r("sortkey")= Initcnt

   
    End If
   
    End If
  Next

很奇怪，一样的代码，刚刚试是正确的，在之前就是在TEMPBOM中有一条记录无法删除。

没有看懂，避免出错的方法：

Public Function GenProductBom(ByVal rootid As Integer,ByVal goid As Integer,ByVal formatstr As String,ByVal NeedTotal As Double,ByVal onetotal As Double) As Boolean
Dim cmd As New SQLCommand
Dim dt As DataTable
cmd.CommandText ="Select goid,singletotal,comgoid,sf_nonstock,ord From {cp_singlebom} Inner JOIN {product} ON {product}.[_Identify] = {cp_singlebom}.[goid]  where {cp_singlebom}.[goid]=" & Cstr(goid)
dt = cmd.ExecuteReader()
Dim r2 As Row = Tables("bomdata").AddNew()
r2("goid") = rootid
r2("nodegoid") = goid
r2("sortkey") = Formatstr
r2("total") = NeedTotal
r2("Singletotal") = onetotal

If dt.DataRows.Count > 0 Then
    For Each dr As DataRow In dt.DataRows
        Dim r As Row = Tables("tempbom").AddNew()
        r("goid")=dr("comgoid")
        r("singletotal") = dr("singletotal")
        r("total") = dr("singletotal") * NeedTotal
        r("sortkey")= Formatstr + "/" + Format(dr("ord"),"000")
    Next
End If

Dim cnt As Integer = DataTables("tempbom").DataRows.Count -1

Do While DataTables("tempbom").DataRows.Count > 0
    Dim r  As DataRow = DataTables("tempbom").DataRows(0)
    Dim dt1 As DataTable
    Dim cmd1 As New SQLCommand
    Dim curgoid As Integer
    Dim fstr As String
    Dim curSingletotal As Double = r("singletotal")
    Dim curTotal As Double = r("total")
    curgoid = r("goid")
    fstr = r("sortkey")
    'MessageBox.Show(cstr(curgoid),"info",MessageBoxButtons.OK,MessageBoxIcon.Information)
    r.Delete
    cmd1.CommandText = "Select goid,singletotal,comgoid,sf_nonstock,ord From {cp_singlebom} Inner JOIN {product} ON {product}.[_Identify] = {cp_singlebom}.[goid]  where {cp_singlebom}.[goid]=" & CSTR(curgoid)
    dt1 = cmd1.ExecuteReader()
   
    If dt1.DataRows.Count > 0 Then
        GenProductBom(rootid,curgoid,fstr,curtotal,cursingletotal)
    Else
        '追加到数据表中
        Dim r1 As Row = Tables("bomdata").AddNew()
        r1("goid") = rootid
        r1("nodegoid") = curgoid
        r1("sortkey") = fstr
        r1("singletotal")=cursingletotal
        'r1("sf_summy")= dr("sf_nonstock")
        r1("total")= curtotal
    End If
Loop
Return True
End Function

Dim cnt As Integer = DataTables("tempbom").DataRows.Count -1

这句代码是用来做诱的吧。。

哈哈。。还是要感谢你的支持和帮助，只要不出错就OK~