"anyeone" wrote:

> I've got a GridView bound to an Object Data Source and I'm having trouble
> figuring out just how to set it up to update properly.
>
> I have the object data source defined as so:
>
> <asp:ObjectDataSource ID="objBatchData" runat="server"
> SelectMethod="GetItems" TypeName="MyNamespace.BatchData"
>     DataObjectTypeName="MyNamespace.BatchItem" UpdateMethod="UpdateItem" >
>     <SelectParameters>
>     <asp:QueryStringParameter Name="BatchID" QueryStringField="BatchID"
> Type="Int32" />
>     </SelectParameters>
>     <UpdateParameters>
>             <asp:Parameter Name="ItemID" Type="Int32" />
>             <asp:Parameter Name="BatchID" Type="Int32" />
>             <asp:Parameter Name="DataField1" Type="string" />
>             <asp:Parameter Name="DataField2" Type="string" />
>     </UpdateParameters>
>     </asp:ObjectDataSource>
>
> .
>
> BatchItem is a business object that defines several constructors.  The
> BatchItem(DataRow row) constructor is the one that GetItems() uses to
> instantiate individual BatchItems when the object data source binding occurs.
>  There is also a BatchItem(int ItemID) constructor and a default constructor
> that doesn't actually do anything.
>
> ItemID and BatchID are read only and brought in through BatchItem on the
> original select statement.  DataField1 and 2 are the two fields actually
> being updated by the user through dropdownlists bound to BatchItem.DataList1
> and BatchItem.DataList2 respectively
>
> The static BatchData.GetItems method seems to be working properly as the
> grid is being populated with the correct data.
>
> The static BatchData.UpdateItem method takes in a BatchItem object (since I
> got an error when I defined it to explicitly take in ItemID, BatchID,
> DataField1, DataField2 saying it needed to take in a BatchItem as a
> parameter).  It then creates a collection of SqlParameters and calls a stored
> proc to perform the update.
>
> The problem is, when the row is updated, the application is instantiating a
> default constructor version of BatchItem which is empty and passing that to
> BatchData.UpdateItem().
>
> So what I need to figure out is how to get the data from the GridView row
> being updated (the four properties listed in "UpdateParameters" on the object
> data source) into the BatchItem that is passed to BatchData.UpdateItem().
>
> I've been using some of Phillip Williams' examples to model from (if you're
> listening, Phillip), particularly the "DropdownList within a GridView"
> example and where I see a disconnect is that the UpdateParameters don't seem
> to be tied to anything in the grid data particularly.  Unfortunately without
> being able to view the source of his UpdateOrder method (the UpdateMethod on
> his object data source) I can't compare what I'm doing to what he is doing to
> see the problem.
>
> Am I supposed to be overriding one of the GridView events to stuff a
> ConfirmItem object with the correct field data?  The UpdateItem method only
> takes ConfirmItem so I don't seem to have access to a parameters collection.
>
> Help is greatly appreciated, thanks!  If you need more information please
> let me know.

"Phillip Williams" wrote:

>
> The update parameters pass scalar values to an object of type clsOrder. 
> Notice that the clsOrder definition,
> http://www.webswapp.com/CodeSamples/ViewSource.aspx?file=\aspnet20\clsOrder.cs,
> has a default constructor (without any parameters defined). It has public
> properties matching the names of the parameters passed through the
> objectDataSource. 
>
> The empty constructor allows the ObjectDatasource to instantiate the class
> then the ObjectDataSource parameters set the public properties of the class
> before passing it to the method specified by the UpdateMethod attribute.
>
> So to answer your question
>
> >… how to get the data from the GridView row being updated
> >(the four properties listed in "UpdateParameters" on the object
> >data source) into the BatchItem that is passed to
> >BatchData.UpdateItem()”
>
> Make sure that your definition of the BatchItem class contains a default
> constructor that receives no parameters, e.g.
>
> Public class BatchItem
> {
>       public BatchItem(){  //default constructor }
>
>       // the rest of the class implementation
> }
>
> --
> HTH,
> Phillip Williams
> http://www.societopia.net
> http://www.webswapp.com
>
>
> "anyeone" wrote:
>
> > I've got a GridView bound to an Object Data Source and I'm having trouble
> > figuring out just how to set it up to update properly.
> >
> > I have the object data source defined as so:
> >
> > <asp:ObjectDataSource ID="objBatchData" runat="server"
> > SelectMethod="GetItems" TypeName="MyNamespace.BatchData"
> >     DataObjectTypeName="MyNamespace.BatchItem" UpdateMethod="UpdateItem" >
> >     <SelectParameters>
> >     <asp:QueryStringParameter Name="BatchID" QueryStringField="BatchID"
> > Type="Int32" />
> >     </SelectParameters>
> >     <UpdateParameters>
> >             <asp:Parameter Name="ItemID" Type="Int32" />
> >             <asp:Parameter Name="BatchID" Type="Int32" />
> >             <asp:Parameter Name="DataField1" Type="string" />
> >             <asp:Parameter Name="DataField2" Type="string" />
> >     </UpdateParameters>
> >     </asp:ObjectDataSource>
> >
> > .
> >
> > BatchItem is a business object that defines several constructors.  The
> > BatchItem(DataRow row) constructor is the one that GetItems() uses to
> > instantiate individual BatchItems when the object data source binding occurs.
> >  There is also a BatchItem(int ItemID) constructor and a default constructor
> > that doesn't actually do anything.
> >
> > ItemID and BatchID are read only and brought in through BatchItem on the
> > original select statement.  DataField1 and 2 are the two fields actually
> > being updated by the user through dropdownlists bound to BatchItem.DataList1
> > and BatchItem.DataList2 respectively
> >
> > The static BatchData.GetItems method seems to be working properly as the
> > grid is being populated with the correct data.
> >
> > The static BatchData.UpdateItem method takes in a BatchItem object (since I
> > got an error when I defined it to explicitly take in ItemID, BatchID,
> > DataField1, DataField2 saying it needed to take in a BatchItem as a
> > parameter).  It then creates a collection of SqlParameters and calls a stored
> > proc to perform the update.
> >
> > The problem is, when the row is updated, the application is instantiating a
> > default constructor version of BatchItem which is empty and passing that to
> > BatchData.UpdateItem().
> >
> > So what I need to figure out is how to get the data from the GridView row
> > being updated (the four properties listed in "UpdateParameters" on the object
> > data source) into the BatchItem that is passed to BatchData.UpdateItem().
> >
> > I've been using some of Phillip Williams' examples to model from (if you're
> > listening, Phillip), particularly the "DropdownList within a GridView"
> > example and where I see a disconnect is that the UpdateParameters don't seem
> > to be tied to anything in the grid data particularly.  Unfortunately without
> > being able to view the source of his UpdateOrder method (the UpdateMethod on
> > his object data source) I can't compare what I'm doing to what he is doing to
> > see the problem.
> >
> > Am I supposed to be overriding one of the GridView events to stuff a
> > ConfirmItem object with the correct field data?  The UpdateItem method only
> > takes ConfirmItem so I don't seem to have access to a parameters collection.
> >
> > Help is greatly appreciated, thanks!  If you need more information please
> > let me know.

"anyeone" wrote:

> Hi Phillip,
>
> I do have a default constructor defined (it is being called properly) and I
> have properties for all of the parameters, however none of the set methods
> are being called on any of the properties.
>
> When I step through the code, first the BatchItem() constructor is called,
> then the UpdateItem(BatchItem) method, but none of the setters are called at
> all.
>
> If I declare the objBatchData_Updating event just so I can take a look at
> the BatchItem being created, I see it is totally empty (as it is when it
> reaches the UpdateItem method).
>
> So it seems that for some reason the application can't figure out to
> automatically call the set methods even though the property names match the
> name and type on the UpdateParameters. 
>
> The only thing I am seeing different is that I have other properties on the
> object that I do not have explicitly listed as UpdateParameters that are
> display only and not needed for the update stored proc - but I don't know why
> that would be a problem.  They all define set methods just in case though.
>
> Any ideas?
>
> Thanks,
> Anye
>

"anyeone" wrote:

> Ok, I tried for yucks making some of the read-only fields editable and as
> soon as I did the set methods started being called - but still not for the
> dropdown list fields (those properties stayed null).
>
> So the problem has to be that the app doesn't know that it has to get the
> new value for the DataField1 and DataField2 fields from the dropdownlists.
>
> What else do I have to do to those particular templates?":
>  <asp:TemplateField HeaderText="Data Field 1">
>             <ItemTemplate>
>                    <asp:Label ID="lblDF1" runat="server"
>                                Text='<%#   Bind("DataField1") %>'></asp:Label>
>              </ItemTemplate>
>               <EditItemTemplate>
>                        <asp:DropDownList ID="ddlDF1" runat="server"
>                             DataSource='<%#Bind("DF1List") %>'              
>    
>                             DataTextField="DF1Description"
>                             DataValueField="DF1Code"></asp:DropDownList>
>                 </EditItemTemplate>
> </asp:TemplateField>