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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_allowCustomText	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_allowCustomText	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. See Example 7.
disable	none	none	Disables the RadComboBox . See Example 7.
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-demand callback 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	Sets the Enabled property of the RadComboBox. To enable/disable the RadComboBox on the client-side, use the .enable() and .disable() methods of the RadComboBox client-side object. See Example 7.
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.
set_selectedIndex	none	integer	Sets the selected Index of the RadComboBox. The method does not actually select an 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.

You can find a complete list of client-side methods for RadComboBox on https://docs.telerik.com/devtools/aspnet-ajax/api/client/Telerik.Web.UI.RadComboBox.

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

JavaScript

		
function AddNewItem() {
    var combo = $find("<%= RadComboBox1.ClientID %>");
    var comboItem = new Telerik.Web.UI.RadComboBoxItem();
    comboItem.set_text("item");
    combo.trackChanges();
    combo.get_items().add(comboItem);
    comboItem.select(); 
    combo.commitChanges();
}

Example 2: Set RadComboBox's text.

JavaScript

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

Example 3: Clear the selection.

JavaScript

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

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

ASPNET

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

<telerik:RadComboBox 
    id="RadComboBox1" 
    runat="server"
    onitemsrequested="RadComboBox1_ItemsRequested">
</telerik:RadComboBox>
<input id="Button1" type="button" value="button" onclick="AddItems()" />

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

JavaScript

	
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.

JavaScript

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

Example 7: Enable/disable RadComboBox on the client-side.

JavaScript

	
function ChangeEnabledState(shouldEnable) {
    var combo = $find("<%= RadComboBox1.ClientID %>");
    if (shouldEnable) {
        combo.enable();
    } else {
        combo.disable();
    }
}

RadComboBox Object

See Also