主题：纠结啊 父表与子表同步加载 代码执行一直出现错误

If DataTables("业务表").DataRows.Count = 0 Then
DataTables("诉讼表").LoadFilter = "[业务编号] Is Null"

DataTables("非诉表").LoadFilter = "[业务编号] Is Null"
DataTables("费用表").LoadFilter = "[业务编号] Is Null"

DataTables("fa piao表").LoadFilter = "[业务编号] Is Null"
DataTables("日程表").LoadFilter = "[业务编号] Is Null"

Else    
Dim ids As String
For Each dr As DataRow In DataTables("业务表").DataRows
    ids = ids & "," & dr("业务编号")
Next
ids= ids.Trim(",")
DataTables("诉讼表").LoadFilter = "[业务编号] In (" & ids & ")"
DataTables("非诉表").LoadFilter = "[业务编号] In (" & ids & ")"
DataTables("费用表").LoadFilter = "[业务编号] In (" & ids & ")"
DataTables("fa piao表").LoadFilter = "[业务编号] In (" & ids & ")"
DataTables("日程表").LoadFilter = "[业务编号] In (" & ids & ")"
End If
DataTables("诉讼表").Load()
DataTables("非诉表").Load()
DataTables("费用表").Load()
DataTables("fa piao表").Load()
DataTables("日程表").Load()

执行以上代码 连续提示5个错误【至少一个值未引用】。。。。  不理解啊 不理解 求教

If DataTables("业务表").DataRows.Count = 0 Then
    DataTables("诉讼表").LoadFilter = "[业务编号] Is Null"

    DataTables("非诉表").LoadFilter = "[业务编号] Is Null"
    DataTables("费用表").LoadFilter = "[业务编号] Is Null"

    DataTables("fa piao表").LoadFilter = "[业务编号] Is Null"
    DataTables("日程表").LoadFilter = "[业务编号] Is Null"

Else 
    Dim ids As String = "'"
    For Each dr As DataRow In DataTables("业务表").DataRows
         ids = ids & "','" & dr("业务编号") & "'"
    Next
    DataTables("诉讼表").LoadFilter = "[业务编号] In (" & ids & ")"
    DataTables("非诉表").LoadFilter = "[业务编号] In (" & ids & ")"
    DataTables("费用表").LoadFilter = "[业务编号] In (" & ids & ")"
    DataTables("fa piao表").LoadFilter = "[业务编号] In (" & ids & ")"
    DataTables("日程表").LoadFilter = "[业务编号] In (" & ids & ")"
End If

DataTables("诉讼表").Load()
DataTables("非诉表").Load()
DataTables("费用表").Load()
DataTables("fa piao表").Load()
DataTables("日程表").Load()