Hi Viv -
Sorry I didn't reply to this sooner but that answer was, at the time, I don't know. i had run off in so many different directions chasing this that I wasn't sure which parts worked and which didn't.
i think now the answer is that I have solved the serialization, which turned out to be easier than I was making it ( code below for lurkers ) and now have it reduced to a problem with Datagridviews using the dataset member as a datasource. (explained below and my current source of frustration)
That first :
I created a small test app with one table, three columns
ikey int pk
company varchar(100)
wideobject varbinary(max)
I have a dataset (Typedchildset) with two datatables ( Clients, Employees)
I have 2 dgvs. For simplicity, I am binding them to the dataset member rather than using a binding source
I enter data the two grids - Clients, then Employees.
Everything saves when serialized as expected - except the last new row of the last grid.
I can add five rows to employees and all save the last will be saved.
NOTE : on further testing - the problem only comes about if the cursor is still in the newly added row when the save is called. If I first click out of the grid to another control, then save, the last row is saved. But of course, the use won't do that, so i must force something so the endedit actually ends the edit for that row.
In the BeforeSave event of my business object :
Me.TypedChildset1.AcceptChanges()
Me.dgvClients.EndEdit()
Me.dgvEmployees.EndEdit()
Dim loFormatter As New BinaryFormatter()
Dim loStream As New System.IO.MemoryStream()
loFormatter.Serialize(loStream, Me.TypedChildset1)
Me.CompaniesBO1.WideObject = loStream.ToArray()
Feel I'm getting very very close, but this last bit is making me crazi(er).
Thoughts?
>Hi,
>Did you solve this?,
>Best,
>Viv
>
>>I have a varchar(max) field in SQL 2008 Dataset_XML. My strongly typed business object is mapped to that column, and returns
>>
>><dsPolicies xmlns="http://tempuri.org/dsPolicies.xsd" />
>>
>>for a null. ( this is because I am adding this field to a current app an have to allow nulls, but I could script this as a value for all null values and then not allow nulls if that would help)
>>
>>dsPolicies is dropped on the form and the instance is names dsPolicies1.
>>
>>The dataset is typed with 8 tables. and the XSD file seems to be working as I am using bindingsources for each table and the datagridviews are showing the right columns.
>>
>>In the parentform_loading event of the business object on the Policies form I am trying to deserialize the XML stored in Me.PoliciesBO1.Dataset_XML ( which has the default value shown above) using this code :
>>
>>
>> Private Sub PoliciesBO1_ParentFormLoading() Handles PoliciesBO1.ParentFormLoading
>>
>> Me.PoliciesBO1.fillall()
>>
>> If Me.PoliciesBO1.Count > 0 Then
>>
>> Me.DsPolicies1 = _ CType(InsurtecPW.Base.Utility.SmartDeSerialize(Me.PoliciesBO1.Dataset_XML), InsurtecPW.dsPolicies)
>>
>> End If
>>
>> End Sub
>>
>>
>>and this is the deserialize routine :
>>
>> Public Shared Function SmartDeSerialize(ByVal serialized As String) As DataSet
>> Dim __ds As DataSet = New DataSet
>> ' needed to create an XML TextReader
>> Dim nt As NameTable = New NameTable
>> Dim nsmgr As XmlNamespaceManager = New XmlNamespaceManager(nt)
>> Dim context As XmlParserContext = New XmlParserContext(Nothing, nsmgr, Nothing, XmlSpace.None)
>> Dim tr As XmlTextReader = New XmlTextReader(serialized, XmlNodeType.Document, context)
>> Try
>>
>> __ds.ReadXml(tr)
>>
>> Return __ds
>> Finally
>> If Not (tr Is Nothing) Then
>> tr.Close()
>> tr = Nothing
>> End If
>> context = Nothing
>> nsmgr = Nothing
>> nt = Nothing
>>
>> End Try
>>
>> End Function
>>
>>
>>As you see, this returns a dataset, but I don't seem to be able to cast the return value as the dsPolicies that I need.
>>
>>Unable to cast object of type 'System.Data.DataSet' to type 'InsurtecPW.dsPolicies'.
>>
>>I have also tried a directcast of the returned dataset and got the same result.
>>
>>This approach seemed to work find when I was using an untyped dataset.
>>
>>I'd appreciate any thoughts on this. I'm pretty clueless about possible differences between the dataset class and a typed dataset or if my problem is the value I am returning if the column is empty.
>>
>>I am open to any approach (including serializing to a byte array) which will allow me to write and entire dataset to a sql column and bring it back.
>>
>>Suggestions very much appreciated.
>>
>>TIA
Charles Hankey
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