以文本方式查看主题

-  Foxtable(狐表)  (http://foxtable.net/bbs/index.asp)
--  专家坐堂  (http://foxtable.net/bbs/list.asp?boardid=2)
----  动态生成关联表问题  (http://foxtable.net/bbs/dispbbs.asp?boardid=2&id=82951)
--  作者：supwork
--  发布时间：2016/3/28 19:41:00
--  动态生成关联表问题
Dim strTableName As String = "订单_主表"
Dim drs As List(Of DataRow)
drs = DataTables("表关联").Select("[主表] = \'" & strTableName & "\'")
For Each dr As DataRow In drs
    Dim Col1a As String() = dr("主表字段").split(",")     ‘处理多关联列
    Dim Col2a As String() = dr("明细表字段").split(",")   ‘处理多关联列
    Dim DataCols1() As DataCol   ‘处理多关联列
    Dim DataCols2() As DataCol   ‘处理多关联列
    Dim glname  As String = dr("关联名称")
    Dim mxtablename As String = dr("明细表")
       For i As Integer = 0 To Col1a.Length - 1
        DataCols1(i) = DataTables(strTableName).DataCols(Col1a(i))   ‘处理多关联列
        DataCols2(i) = DataTables(mxtablename).DataCols(Col2a(i))    ‘处理多关联列
    Next
    Relations.Add(glname, DataCols1, DataCols2)
Next 

请教红色部份代码怎么也能不过

提示：

---------------------------
版本:2015.12.22.1
---------------------------
代码执行出错，错误信息：



System.NullReferenceException: 未将对象引用设置到对象的实例。

   在 UserCode.Test()
---------------------------
确定   
---------------------------



代码改成

Dim strTableName As String = "订单_主表"
Dim drs As List(Of DataRow)
drs = DataTables("表关联").Select("[主表] = \'" & strTableName & "\'")
For Each dr As DataRow In drs
    Dim Col1a As String() = dr("主表字段").split(",")
    Dim Col2a As String() = dr("明细表字段").split(",")
    Dim js As Integer = Col1a.Length
    Dim DataCols1(js) As DataCol
    Dim DataCols2(js) As DataCol
    Dim glname  As String = dr("关联名称")
    Dim mxtablename As String = dr("明细表")
    \'Functions.Execute("HuaDataTableJg",mxtablename)
msgbox(1)
    For i As Integer = 0 To js - 1
        DataCols1(i) = DataTables(strTableName).DataCols(Col1a(i))
        DataCols2(i) = DataTables(mxtablename).DataCols(Col2a(i))
    Next
msgbox(2)
    Relations.Add(glname,DataCols1,DataCols2,True,1)
Next \'


则这一句 增加关联表通不过
[此贴子已经被作者于2016/3/28 19:51:45编辑过]
--  作者：大红袍
--  发布时间：2016/3/28 19:51:00
--  
Dim DataCols1(Col1a.length-1) As DataCol   Dim DataCols2(Col2a.length-1) As DataCol   ‘处理多关联列
[此贴子已经被作者于2016/3/28 19:52:26编辑过]
--  作者：supwork
--  发布时间：2016/3/28 19:53:00
--  
报错

---------------------------
版本:2015.12.22.1
---------------------------
代码执行出错，错误信息：



System.NullReferenceException: 未将对象引用设置到对象的实例。

   在 Foxtable.DataRelationCollection.Add(String RelationName, DataCol[] ParentCols, DataCol[] ChildCols, Boolean Visible, RelationPathEnum RelationTable)

   在 UserCode.Test()
---------------------------
确定   
---------------------------
--  作者：supwork
--  发布时间：2016/3/28 19:58:00
--  
好了  谢谢

--  作者：大红袍
--  发布时间：2016/3/28 19:58:00
--  
    Dim DataCols1(js-1) As DataCol
    Dim DataCols2(js-1) As DataCol