Question

I want to give validations to the spark combobox when user enters a value other than the value in the dataprovider of that combobox.Can any one give me the code how to give validation if user enters a value other than the value in the dataprovider and on focus change validation should occur.
Thanks

Answer 1

you can set the property textInput to the combobox, and manage the check on input from the associated function…

<fx:Script>
    <![CDATA[
        protected function change(event:TextEvent):void
        {

        }
    ]]>
</fx:Script>

<s:ComboBox  textInput="change(event)"/>

flash.display.InteractiveObject.textInput

Dispatched when a user enters one or more characters of text. Various text input methods can
generate this event, including standard keyboards, input method
editors (IMEs), voice or speech recognition systems, and even the act
of pasting plain text with no formatting or style information.

Event Type:
flash.events.TextEvent.TEXT_INPUT

EDIT

<fx:Script>
    <![CDATA[
        import mx.collections.ArrayCollection;
        import mx.controls.Alert;
        import mx.events.FlexEvent;
        //dataprovider initialization
        [Bindable]private var d:ArrayCollection = new ArrayCollection([
            {name: "Values 1"}, {name: "Values 2"}, {name: "Values 3"}
            ]);

        protected function change(event:TextEvent):void
        {      // if enter key is pressed
            if (event.text.charAt(event.text.length-1) == "\r")
            {       
                // if the text inserted in the combobox is one of the 
                // item in the dataprovider 
                if (comboBox.selectedIndex >= 0)
                    Alert.show("something selected");
                else   // if the text is not an item in the dataprovider
                    Alert.show("nothing selected");

            }
        }
    ]]>
</fx:Script>

<s:ComboBox id="comboBox" textInput="change(event)"
       dataProvider="{d}" labelField="name"/>

EDIT 2

To set the border color from actionscript you can do:

comboBox.setStyle("borderColor","#ff0000"); // set the bordercolor to red

If you do not need particular check on the text inserted you can simply set the property change on the ComboBox

        protected function index_change(event:IndexChangeEvent):void
        {
            if (comboBox.selectedIndex >= 0 )
                Alert.show("something selected")
            else
                Alert.show("nothing selected");

        }
        <s:ComboBox id="comboBox" dataProvider="{d}" labelField="name"
            change="index_change(event)"
             />