Hierarchy Grid with list object defined

[samuel]

I use C # with Visual Studio 2010.
I use an class Order and I have a property <OrderDetail> List. And I would use a grid to binding my class and to use the hierarchy to display also OrderDetail. But I do not know how. Can you explain to me?

Here are my classes simplified

{
    public Order()
    {
    }

    public int Id {get;set;}
    public List<OrderDetail> ListOrderDetail {get;set;}
}
public class OrderDetail
{
    public OrderDetail()
    {
    }
    public string Article{get;set;}
    public int Qte {get;set;}
    public double Price {get;set;}
    public double PriceHT {get {return Qte*Price;}}
}

Thank you in advance

[Veli]

Hello samuel,

There are a couple of approaches you can take for setting up a hierarchical RadGrid with the given object structure. You can use RadGrid's NeedDataSource event to bind RadGrid to the Orders collection you have. You can then use the DetailTableDataBind event to bind the detail tables to their parent Order item's child collection (ListOrderDetail) in your case:

protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
{
    List<Order> orders = new List<Order>();
    //populate orders here
    RadGrid1.DataSource = orders;
}

protected void RadGrid1_DetailTableDataBind(object sende, GridDetailTableDataBindEventArgs e)
{
    e.DetailTableView.DataSource = ((Order)e.DetailTableView.ParentItem.DataItem).ListOrderDetail;
}

The markup for the above example is:

<telerik:RadGrid ID="RadGrid1" runat="server" Width="800px"
    OnNeedDataSource="RadGrid1_NeedDataSource"
    OnDetailTableDataBind="RadGrid1_DetailTableDataBind">
    <MasterTableView HierarchyLoadMode="ServerBind">
        <DetailTables>
            <telerik:GridTableView>
            </telerik:GridTableView>
        </DetailTables>
    </MasterTableView>
</telerik:RadGrid>

Note the HierarchyLoadMode of the MasterTableView. It should be set to either ServerBind or Client. This setting is required, so that all your detail tables are databound when the parent items bind and you have access to the DataItem (which is the Order object in our case) of the parent item from the nested  table:

e.DetailTableView.ParentItem.DataItem

If you want to use LoadOnDemand hierarchy binding, you cannot use the e.DetailTableView.ParentItem.DataItem property. You will have to retrieve the Order object of the parent item separately from your data source to bind to its child ListOrderDetail collection.

Attaching a test page to demonstrate the above approach.

Greetings,
Veli
the Telerik team

[samuel]

Thank you very much for your help

[JJ]

I used your sample to work on my grid to bind to the collections.  When I set detail table allow to paging and set page size to 2 using your attached sample,  The detail table paging fails .

 

<telerik:gridtableview Name="Detail" PageSize="2">

 

 

</telerik:gridtableview>

((Order)e.DetailTableView.ParentItem.DataItem).ListOrderDetail becomes null when detail table deos the paging.

Can you please help?

Thanks!

 

[Marin]

Hi Jj,

 The DataItem property of the Parent item is not persisted when paging in the details table you can use the ItemIndex property instead to extract the correct item from the datasource and bind the detail table:

var item = GetItemByIndex(e.DetailTableView.ParentItem.ItemIndex); //method that gets the item from the the datasource by its index
e.DetailTableView.DataSource = item.ListOrderDetail;

Hope this helps.Regards,
Marin
the Telerik team

[JJ]

Thanks!

What is GetItemByIndex?     radgrid function? can you give me more detail? 

[Veli]

What Marin meant is that you need to find your data object from the data source that corresponds to the parent data item of the detail table. Once you retrieve the data object, you can bind the detail table to this object's child collection. You can find the parent data object either by the sequential ItemIndex of the parent GridDataItem instance (retrieved by e.DetailTable.ParentItem.ItemIndex), or by a data key value you have specified (using the e.DetailTable.ParentItem.GetDataKeyValue() method).

Veli
the Telerik team