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Data binding error when adding children to new parents.

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GridView

This is a migrated thread and some comments may be shown as answers.

Craig asked on 07 Feb 2013, 06:38 PM

Hi
I am having difficulty with databinding and child objects with the RadGridview control.
I have a custom object that exposes two properties; a string and a collection (List<>) of child objects. The child objects only expose a single string property.
If I load a number of instances of the custom object each with children, into an Observable collection, the databinding seems to work and I can add new children to the existing parents without any problem.
However, if I add a new parent, when I attempt to add a new child there are databinding errors stating the property name cannot be found and the child is not retained in the child table in the grid control. (BindingExpression path error: 'FloorNo' property not found on 'object' ''Object').
I'm using the MVVM pattern so I am trying to define the hierarchy in the XAML which I've listed below.
Note: Buildings is the observable collection of the custom object Building.
BuildingNo is the string property of Building and Floors is the List<Floor> property where Floor is the child object. FloorNo is the string property of Floor.
Please can you suggest what I need to do to correct or improve the XAML to enable the creation of new children in new parents?
Thanks
Craig

<telerik:RadGridView HorizontalAlignment="Left" Margin="378,0,0,262" Name="buildingsGridView" VerticalAlignment="Bottom" Width="193" Height="197"

ItemsSource="{Binding Buildings, Mode=TwoWay}" AutoGenerateColumns="False" ShowGroupPanel="False" ShowInsertRow="True"

RowHeight="23" RowIndicatorVisibility="Collapsed" ScrollViewer.HorizontalScrollBarVisibility="Disabled"

CanUserFreezeColumns="False" CanUserReorderColumns="False" CanUserResizeColumns="True" SelectedItem="{Binding SelectedBuilding}">

<telerik:RadGridView.Columns>

<telerik:GridViewDataColumn DataMemberBinding="{Binding BuildingNo}" Header="Building No." IsFilterable="False" IsGroupable="False" IsReorderable="False" IsResizable="False" ShowDistinctFilters="False" Width="*"/>

</telerik:RadGridView.Columns>

<telerik:RadGridView.ChildTableDefinitions>

<telerik:GridViewTableDefinition>

<telerik:GridViewTableDefinition.Relation>

<telerik:PropertyRelation ParentPropertyName="Floors" />

</telerik:GridViewTableDefinition.Relation>

</telerik:GridViewTableDefinition>

</telerik:RadGridView.ChildTableDefinitions>

<telerik:RadGridView.HierarchyChildTemplate>

<DataTemplate>

<telerik:RadGridView ItemsSource="{Binding Floors, Mode=TwoWay}" Name="floorsGrid" ShowGroupPanel="False" AutoGenerateColumns="False">

<telerik:RadGridView.Columns>

<telerik:GridViewDataColumn DataMemberBinding="{Binding FloorNo}" Header="Floor No." IsFilterable="False" IsGroupable="False" IsReorderable="False" IsResizable="False" ShowDistinctFilters="False" Width="*" />

</telerik:RadGridView.Columns>

</telerik:RadGridView>

</DataTemplate>

</telerik:RadGridView.HierarchyChildTemplate>

</telerik:RadGridView>

Data binding error when adding children to new parents.

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