RadComboBox does not do anything specific in this case, i.e. it does not iterate through the result returned by GetItems unless the request is a callback and the control's EnableAutomaticLoadOnDemand
property is set to true
. You can set the property to false and see the same effect.
What is more, if you test the exact same setup with a DropDownList control, the same will happen. Even the first page load hits the database.
This stems from the OnLoad method of the DataBoundControl, which we and all data bound ASP.NET controls inherit.
You can test with the following code:
DropDownListNoOnLoad : DropDownList
sender, EventArgs e)
var ddl =
ddl.DataSource = GetResults();
var results = from h
ContactName = h.ContactName
As a workaround to this you can set the DataSource property only during callback requests sent by the corresponding RadComboBox:
I hope this helps.
the Telerik team
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