Custom Hierarchy: Adding ChildTableDefinitions to the expandable row creates exception

[Jitin Vishwakarma]

Hi,

I had a piece of code to add hierarchy to the GridView that works fine in version Q2 2009. I add Child grid at runtime where I cannot even use the binding because the structure of the data is not defined and is based on user interactions.
I had a code that looked something like this:

void TableDefinition_PreviewDataRecordCreate(object sender, DataRecordCreateEventArgs e)
{
GridViewTableDefinition detailDefinition = new GridViewTableDefinition();
detailDefinition.AutoGenerateFieldDescriptors = false;

// create colMultiplier
detailDefinition.FieldDescriptors.Add(colMultiplier);

// Create Data Source for Child Nodes
var sourceDataRecs = new List<object>();
// fill sourceDataRecs

detailDefinition.DataSource = sourceDataRecs;
e.IsExpandableRecord = true;
e.ChildTableDefinitions.Add(detailDefinition);
e.GridViewDataControl.ChildTableDefinitions.Add(detailDefinition);
}

This is replaced by the following code in Q3:
    private void radTargetGridNodes_RowLoaded(object sender, RowLoadedEventArgs e)
    {
        GridViewTableDefinition detailDefinition = new GridViewTableDefinition();
        detailDefinition.AutoGenerateFieldDescriptors = false;
        detailDefinition.FieldDescriptors.Add(colMultiplier);

        // Create Data Source for Child Nodes
        var sourceDataRecs = new List<object>();

        detailDefinition.DataSource = sourceDataRecs;        
        ((GridViewRow)e.Row).IsExpandable = true;
        e.GridViewDataControl.ChildTableDefinitions.Add(detailDefinition);  ----> THIS LINE CREATES EXCEPTION
        /// Exception - HRESULT E_FAIL  Managed RunTime Error #4004
    }

Would there be a better way to do this?

Thanks,
Jitin

[Vlad]

Hi,

Since PreviewDataRecordCreate you can use a bit different approach to achieve custom hierarchy demonstrate here:
http://demos.telerik.com/silverlight/#GridView/Hierarchy/CustomHierarchy

Regards,
Vlad
the Telerik team

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[Jitin Vishwakarma]

Hi Vlad,

If you look closely in the code provided above, I am using RowLoaded event for Q3 instead of PreviewDataRecordCreate.
I have seen the Demo/examples code for Q3. But the whole point for my question is that I cannot bind the child rows until during runtime. That is the reason why I had to add GridViewTableDefinition instance to ChildTableDefinitions of the parent row. Why does this no longer work in Q3? Or am I doing something wrong?

Thanks,
Jitin

[Vlad]

Hi Jitin,

Sorry, I've missed this!

Still you do not need to add child tables dynamically - please check the demo I've posted in my previous reply.

Kind regards,
Vlad
the Telerik team

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[Frank Gusche]

Hi,

I have exactly the same problem. It's not possible to add a GridViewTableDefinition in code behind.
You always get the error "HRESULT E_FAIL ...".
Sorry Vlad, the demo isn't helpful.

Any other ideas?

Thanks,
Frank

[Vlad]

Hello Frank,

Can you post more info why you need to add child tables dynamically? Our demo demonstrate how to create custom hierarchy - why the demo is not helpful? Please clarify.

Best wishes,
Vlad
the Telerik team

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Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Frank Gusche]

Hi Vlad,

my colleague had solved the problem.
In the new version you have to define a "ChildTableDefinition" in the foreground-code.

<telerikGridView:RadGridView
                        Grid.Row="1"
                        Margin="10"
                        ItemsSource="{Binding Holdings}"
                        x:Name="_gridHolding"
                        ColumnsWidthMode="None"
                        ShowGroupPanel="False"
                        IsReadOnly="True"
                        ScrollMode="RealTime"
                        AutoGenerateColumns="True">

                            <telerikGridView:RadGridView.ChildTableDefinitions>
                                <telerikGridView:GridViewTableDefinition>

                                </telerikGridView:GridViewTableDefinition>
                            </telerikGridView:RadGridView.ChildTableDefinitions>
                            <telerikGridView:RadGridView.HierarchyChildTemplate>
                                <DataTemplate>
                                    <StackPanel>
                                        <telerikGridView:RadGridView
                                                AutoGenerateColumns="True"
                                                x:Name="_gridTransactions"
                                                ShowGroupPanel="False"
                                                IsReadOnly="True"
                                                Loaded="_gridTransactions_Loaded"
                                                >
                                        </telerikGridView:RadGridView>
                                    </StackPanel>
                                </DataTemplate>
                            </telerikGridView:RadGridView.HierarchyChildTemplate>

                        </telerikGridView:RadGridView>

At the outer grid you can now define a "RowLoaded-Event":

void _gridHolding_RowLoaded(object sender, Telerik.Windows.Controls.GridView.RowLoadedEventArgs e)
        {
            GridViewRow row = e.Row as GridViewRow;
            InstrumentsHoldings holding = e.DataElement as InstrumentsHoldings;

            if(row != null && holding != null)
            {
                row.IsExpandable = true;

                GridViewTableDefinition detailDefinition = new GridViewTableDefinition();
...
}

In the inner grid you have to define a "Loaded-Event" where you bind your data.

private void _gridTransactions_Loaded(object sender, RoutedEventArgs e)
        {
            var k = sender as GridViewDataControl;

            var cont = k.ParentRow.DataContext;

            k.ItemsSource = ItemsSource;
        }

When you haven't the "ChildTableDefinitions" in the foreground-code and want do add some from the code behind then the error "HRESULT E_FAIL ..." occurs.


That worked for me!

Hope it helps.


Regards,
Frank

[John]

The demo link does not seem to be working.  I keep getting redirected to install Silverlight, which is definitely installed on my system. 

I have the same problem, but really I don't know how to do this any other way.  We have an XML column in the parent data that we display dynamically as a child table.  The XML can vary from row to row, so I create the child table on the fly.  I can't seem to get this to work on the row loaded event.  Here are a few snippets:

private void DetailsGrid_RowLoaded(object sender, RowLoadedEventArgs e)

{

GridViewRow row = e.Row as GridViewRow;

if (row != null)

{

if (row.DataContext is DDO_SimpleXMLBaseClass)

{

DDO_XMLBaseClassData data = (DDO_XMLBaseClassData)row.DataContext;

if (data.TransactionXml.Count() > 0)

{

row.IsExpandable = true;

e.GridViewDataControl.ChildTableDefinitions.Add(getTableDefFromXML(data.TransactionXml[0].ToString()));

}  ...

       private GridViewTableDefinition getTableDefFromXML(string xml)
        {
            GridViewTableDefinition detailDefinition = new GridViewTableDefinition();
            XmlDataProvider xdp = new XmlDataProvider();
            xdp.IsAsynchronous = false;
            System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
            doc.LoadXml(xml);
            xdp.Document = doc;
            xdpxdp.XPath = xdp.Document.FirstChild.Value;
            xdp.XPath = "/" + doc.DocumentElement.Name;
            detailDefinition.DataSource = new ObservableCollection<XmlNode>((IEnumerable<XmlNode>)xdp.Data);
            return detailDefinition;
        }

Not sure what to try at this point.
Thanks

John

[Vlad]

Hello,

Can you post more info about your Silverlight version? I've just tried the demo using both Silverlight 3 and Silverlight4 and everything worked as expected.

Kind regards,
Vlad
the Telerik team

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