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AutoCompleteBoxPropertiesBase.LoadDropDownOnDemand Property

Gets or sets a value specifying whether the HTML code that represents the editor’s drop-down window should be loaded via a callback on demand.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v24.1.dll

NuGet Package: DevExpress.Web


public bool LoadDropDownOnDemand { get; set; }

Property Value

Type Default Description
Boolean false

true, to load the drop-down window render on demand; otherwise, false.


Set the LoadDropDownOnDemand property to true to load an editor’s drop-down window (its complete HTML markup) via a callback on demand. This might significantly reduce the page size and the initial load time when a page contains a lot of combo box editors (e.g., when you use ASPxComboBox controls within an ASPxGridView control).

Note that HTML markup for the drop-down window is loaded via a callback on demand only once. When the drop-down window content is loaded on the client side, the control operates with the loaded data.

On the client side, to ensure that the drop-down window markup is loaded, use the ASPxClientComboBox.EnsureDropDownLoaded method.


The LoadDropDownOnDemand property synchronizes its value with the editor’s ASPxAutoCompleteBoxBase.LoadDropDownOnDemand property.


If you bind a control to a large data source at runtime (e.g., on Init event), it can increase the initial page load time. In this case, setting the LoadDropDownOnDemand property to true makes no sense.

We recommend you use the LoadDropDownOnDemand property together with ComboBoxProperties.ItemRequestedByValue and ComboBoxProperties.ItemsRequestedByFilterCondition events.

See Also