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RadComboBox Object

This article explains about the methods of the RadComboBox client-side object. The RadComboBox client API allows for complete control over the client object, giving the developer the opportunity to set the behavior of the control depending on the scenario.


Telerik has removed the tlrkComboBoxes array from the RadComboBox object. You should use Telerik.Web.UI.RadComboBox.ComboBoxes instead - which you can use to obtain an array containing all the client-side RadComboBox instances.

The following table lists the most important methods of the client-side RadComboBox object:


Name Parameters Return Type Description
trackChanges none none Starts tracking changes made to RadComboBox that will be preserved over postbacks. See Example 1.
commitChanges none none Writes the changes to RadComboBox that were made since a previous call to trackChanges , so that they are preserved over postbacks. Client-side changes are available on the server after postback. You can use the ClientChanges property to access them. See Example 1.
set_text (string text) none Sets the text of the input field to the value of the specified parameter. See Example 2.
get_text none string Gets the text of the input field.
get_checkedItems none array Gets an array of the checked RadComboBoxItem objects.
get_lastWord none string Gets the word after the last separator in the text of RadComboBox input field. If a separator is not set, returns the text itself.
set_allowCustomEntry Boolean none Allows/Disallows the users to type text in the input area, when called with 'false' as a parameter - the input area contains only the currently selected item's text, or text obtained by all selected items' texts separated by comma or other character.
get_allowCustomEntry none Boolean Returns true the users are allowed to type random text in the input area, false otherwise.
set_emptyMessage (string text) none Sets the EmptyMessage text of RadComboBox input field.
get_emptyMessage none string Gets the EmptyMessage text of RadComboBox input field.
set_value (string value) none Sets the value of RadComboBox .
get_value none string Gets the value of RadComboBox .
showDropDown none none Opens the drop-down list.
set_closeDropDownOnBlur Boolean none If you call the showDropDown / toggleDropDown method on a button click, you will have to use combo.set_closeDropDownOnBlur(false) right before you call the showDropDown / toggleDropDown method, otherwise the drop-down area will flicker instead of open. Then, you should use combo.set_closeDropDownOnBlur(true) in the OnClientBlur event handler. You can see a demo at: Add/Remove/Disable Items
hideDropDown none none Closes the drop-down list.
toggleDropDown none none Toggles the drop-down list.
enable none none Enables the RadComboBox .
disable none none Disables the RadComboBox .
findItemByValue (string value) RadComboBoxItem Returns the first RadComboBoxItem object whose Value property equals the passed parameter.
findItemByText (string text) RadComboBoxItem Returns the first RadComboBoxItem object whose Text property equals the passed parameter.
findFirstMatch string RadComboBoxItem Returns the first RadComboBoxItem object whose Text contains the string passed as parameter.
clearItems none none Clears all items of RadComboBox .
clearSelection none none Clears the selection. See Example 3.
requestItems (string text, Boolean) none Initiates a load-on-demandcallback request with the specified text, causing the ItemsRequested server event to fire or a request to be sent to a web service. The second Boolean parameter instructs the RadComboBox to append the new items ( True ) or clear items ( False ). See Example 4.
get_id none string Gets the server-side ID of the RadComboBox instance.
get_dropDownElement none DOM object Gets a reference to the drop-down list.
get_inputDomElement none DOM object Gets a reference to the input area. See Example 5.
get_imageDomElement none DOM object Gets a reference to image element (drop-down toggle). See Example 6.
get_moreResultsBoxElement none DOM object Gets a reference to the MoreResultsBox image element.
get_moreResultsBoxMessageElement none DOM object Gets a reference to the MoreResultsBox Message element.
get_dropDownVisible none Boolean True if the drop-down is opened.
set_enabled Boolean none Enables/disables the RadComboBox.
get_enabled none Boolean True if RadComboBox is enabled.
get_selectedItem none RadComboBoxItem Gets the currently selected item.
get_selectedIndex none integer Gets the index of the currently selected item.
get_items none RadComboBoxItemCollection Returns the items collection for RadComboBox .
get_enableItemCaching none boolean True if item caching is enabled (applicable in load-on-demand scenario).
set_enableItemCaching boolean none Enables/disables item caching (applicable in load-on-demand scenario).
attachDropDown none none Attach the drop down list to the input element if it is not aligned properly, especially when a postback fires from a templated item. Use it in this scenario: Ajaxified control in ItemTemplate does a full postback.
get_visibleItems none array Returns all visible items.
setAllItemsVisible Boolean none Sets all items visible / invisible.
get_changeText none Boolean True if ChangeTextOnKeyBoardNavigation is true .
set_changeText Boolean none Sets the ChangeTextOnKeyBoardNavigation property.
get_enableTextSelection none Boolean True if EnableTextSelection is True .
set_enableTextSelection boolean none Sets the EnableTextSelection property.
get_markFirstMatch none Boolean True if MarkFirstMatch is true .
set_markFirstMatch Boolean none Sets the MarkFirstMatch property.
clearCache none none Clears the items cache if EnableItemCaching is True .
get_highlightedItem none RadComboBoxItem Gets the currently highlighted item.

Example 1: Add a new item and persist it after a postback.

function AddNewItem() {
    var combo = $find("<%= RadComboBox1.ClientID %>");
    var comboItem = new Telerik.Web.UI.RadComboBoxItem();

Example 2: Set RadComboBox's text.

function SetTextOfTheComboBox() {
    var combo = $find("<%= RadComboBox1.ClientID %>"); 

Example 3: Clear the selection.

function ClearSelection() {
    var combo = $find("<%= RadComboBox1.ClientID %>");

Example 4: Initiate a load-on-demand callback request with the specified text.

<script language="javascript" type="text/javascript">
function AddItems() {
    var combo = $find("<%= RadComboBox1.ClientID %>"); 
    combo.requestItems("Item1", true);

<input id="Button1" type="button" value="button" onclick="AddItems()" />

Example 5: Set the background-color of the input area.

function ChangeInputColor() {
    var combo = $find("<%= RadComboBox1.ClientID %>");
    var inputArea = combo.get_inputDomElement();
    inputArea.style.backgroundColor = "red" 

Example 6: Set the image DOM element's src attribute.

function ChangeImageElement() {
    var combo = $find("<%= RadComboBox1.ClientID %>");
    var image = combo.get_imageDomElement();
    image.src = "MyImage.gif"; 

See Also