Events
RadComboBox supports a number of client-side events that let you customize its behavior:
OnClientItemsRequestFailed occurs when the load-on-demand callback error appears.
OnClientBlur occurs when RadComboBox loses focus.
OnClientDropDownOpening occurs before the drop-down list opens.
OnClientDropDownOpened occurs after the drop-down list has been opened.
OnClientDropDownClosing occurs before the drop-down list closes.
OnClientDropDownClosed occurs after the drop-down has been closed.
OnClientFocus occurs when RadComboBox has just received input focus.
OnClientItemsRequesting occurs when the user triggers the load-on-demand mechanism by typing in the input area or clicking the drop-down toggle of RadComboBoxx. This event fires before the items are added.
OnClientItemsRequested occurs immediately after the load-on-demand mechanism has bound new items to RadComboBox.
OnClientKeyPressing occurs when a RadComboBox item is selected and the user presses a key.
OnClientSelectedIndexChanging occurs before the selected item is changed in response to a user action.
OnClientSelectedIndexChanged occurs after the selected item has been changed in response to a user action.
OnClientItemChecking occurs when a particular item is about to be checked.
OnClientItemChecked occurs after the selected item has been changed in response to a user action.
OnClientLoad occurs after the RadComboBox has been fully initialized on the client-side.
OnClientTextChange occurs when the text in the input area has been changed.
OnClientItemDataBound occurs for each item that is created during Web Service Load on Demand (available after Q3 SP2 2008).
OnClientTemplateDataBound occurs after the client template is bound and the binding expression are evaluated.
OnClientCheckAllChecking occurs before the check all items check box is checked.
OnClientCheckAllChecked occurs after the check all items check box is checked.
To use these events, simply write a JavaScript function that can be called when the event occurs. Then assign the name of the JavaScript function as the value of the the corresponding RadComboBox property.
<script language="javascript" type="text/javascript">
function MyClientBlur(sender, eventArgs) {
alert("blur");
}
</script>
<telerik:radcombobox
id="RadComboBox1"
runat="server"
onclientblur="MyClientBlur">
</telerik:radcombobox>
You can also assign event handlers in client-side code:
function MyClientBlur(sender, eventArgs) {
alert("blur");
}
function pageLoad() {
var combo = $find("<%= RadComboBox1.ClientID %>");
combo.add_onClientBlur(MyClientBlur);
}
Another advantage of the client-side API is that you can detach an event handler dynamically:
function RemoveEventHandler() {
var combo = $find("<%= RadComboBox1.ClientID %>");
combo.remove_onClientBlur(MyClientBlur);
}
Note that on the client-side, the names of events are slightly different than on the server side. The following table shows the correspondance between client-side and server-side names:
Client-SideName | Server-Side Name | Methods to Add and Remove |
---|---|---|
OnClientLoad | load | add_load, remove_load. |
OnClientKeyPressing | keyPressing | add_keyPressing, remove_keyPressing. |
OnClientSelectedIndexChanging | selectedIndexChanging | add_selectedIndexChanging, remove_selectedIndexChanging. |
OnClientSelectedIndexChanged | selectedIndexChanged | add_selectedIndexChanged, remove_selectedIndexChanged. |
OnClientItemsRequesting | itemsRequesting | add_itemsRequesting, remove_itemsRequesting. |
OnClientItemsRequested | itemsRequested | add_itemsRequested, remove_itemsRequested. |
OnClientDropDownOpening | dropDownOpening | add_dropDownOpening, remove_dropDownOpening. |
OnClientDropDownOpened | dropDownOpened | add_dropDownOpened, remove_dropDownOpened. |
OnClientDropDownClosing | dropDownClosing | add_dropDownClosing, remove_dropDownClosing. |
OnClientDropDownClosed | dropDownClosed | add_dropDownClosed, remove_dropDownClosed. |
OnClientItemsRequestFailed | itemsRequestFailed | add_itemsRequestFailed, remove_itemsRequestFailed. |
OnClientFocus | onClientFocus | add_onClientFocus, remove_onClientFocus. |
OnClientBlur | onClientBlur | add_onClientBlur, remove_onClientBlur. |
OnClientTextChange | textChange | add_textChange, remove_textChange. |
OnClientItemDataBound | itemDataBound | add_itemDataBound, remove_itemDataBound. |