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TreeListCalculatedColumn raise exception if RadTreeList AllowLoadOnDemand = true

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TreeList

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3 Answers, 1 is accepted

answered on 24 Sep 2012, 10:56 AM

Hello Robert,

Please note that in case AllowLoadOnDemand is set to rue for the RadTreeListControl except of assigning datasource in NeedDataSource event for the control you should handle the RadTreeList.ChildItemsDataBind event and select the subset of items related to the expanded item. See the help topic below and verify if you follow the correct logic for achieving the required functionality:
http://www.telerik.com/help/aspnet-ajax/treelist-load-on-demand.html

Kind regards,
Maria Ilieva
the Telerik team

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answered on 24 Sep 2012, 11:58 AM

Hi Maria,



I do handle both event NeedDataSource and ChildItemsDataBind





protected

void MyRadTreeList_NeedDataSource(object sender, TreeListNeedDataSourceEventArgs e)

{

MyTreeList.DataSource = DataManager.Current.GetData();

Debug.WriteLine("TreeList_NeedDataSource");

}

protected void MyRadTreeList_OnChildItemsDataBind(object sender, TreeListChildItemsDataBindEventArgs e)

{

int l_parentId = Convert.ToInt32(e.ParentDataKeyValues["Id"].ToString());

e.ChildItemsDataSource = DataManager.Current.GetData(l_parentId);

Debug.WriteLine(string.Format("TreeList_OnChildItemsDataBind:[{0}] ", l_parentId));

}

<telerik:RadTreeList ID=MyTreeList runat="server" DataKeyNames="Id" ParentDataKeyNames="ParentId"

AllowLoadOnDemand="false" AutoGenerateColumns="False"

OnNeedDataSource="MyRadTreeList_NeedDataSource"

OnChildItemsDataBind="MyRadTreeList_OnChildItemsDataBind">

<Columns>

<telerik:TreeListBoundColumn DataField="Id" HeaderText="Id" />

<telerik:TreeListBoundColumn DataField="Name" HeaderText="Name" />

<telerik:TreeListBoundColumn DataField="Value1" HeaderText="Value1" />

<telerik:TreeListBoundColumn DataField="Value2" HeaderText="Value2" />

<telerik:TreeListCalculatedColumn DataFields="Value1,Value2" Expression="{0}+{1}" HeaderText="Sum" UniqueName="SumColumn" />

</Columns>

</telerik:RadTreeList>

Column <telerik:TreeListCalculatedColumn DataFields="Value1,Value2" Expression="{0}+{1}" HeaderText="Sum" UniqueName="SumColumn" /> raises an exception.