Setting a border color on the ComboBox control in Flex

The following example shows how you can set the border color on a Flex ComboBox control by setting the (drumroll) borderColor style.

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/09/setting-a-border-color-on-the-combobox-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">

    <mx:Array id="arr">
        <mx:Object label="One" />
        <mx:Object label="Two" />
        <mx:Object label="Three" />
        <mx:Object label="Four" />
        <mx:Object label="Five" />
        <mx:Object label="Six" />
    </mx:Array>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="borderColor:">
                <mx:ColorPicker id="colorPicker" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:ComboBox id="comboBox"
            dataProvider="{arr}"
            borderColor="{colorPicker.selectedColor}" />

</mx:Application>

View source is enabled in the following example.

You can also set the borderColor style in an external .CSS file or <mx:Style /> block, as seen in the following example:

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/09/setting-a-border-color-on-the-combobox-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">

    <mx:Style>
        ComboBox {
            borderColor: red;
        }
    </mx:Style>

    <mx:Array id="arr">
        <mx:Object label="One" />
        <mx:Object label="Two" />
        <mx:Object label="Three" />
        <mx:Object label="Four" />
        <mx:Object label="Five" />
        <mx:Object label="Six" />
    </mx:Array>

    <mx:ComboBox id="comboBox"
            dataProvider="{arr}" />

</mx:Application>

Or, you can set the borderColor style using ActionScript, as seen in the following example:

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/09/setting-a-border-color-on-the-combobox-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.events.ColorPickerEvent;

            private function colorPicker_change(evt:ColorPickerEvent):void {
                comboBox.setStyle("borderColor", evt.color);
            }
        ]]>
    </mx:Script>

    <mx:Array id="arr">
        <mx:Object label="One" />
        <mx:Object label="Two" />
        <mx:Object label="Three" />
        <mx:Object label="Four" />
        <mx:Object label="Five" />
        <mx:Object label="Six" />
    </mx:Array>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="borderColor:">
                <mx:ColorPicker id="colorPicker"
                        change="colorPicker_change(event);" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:ComboBox id="comboBox"
            dataProvider="{arr}" />

</mx:Application>

Finally, due to popular demand, here is the “same” example in a more ActionScript friendly format:

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/09/setting-a-border-color-on-the-combobox-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        xmlns:comps="comps.*"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">

    <comps:MyComp />

</mx:Application>

comps/MyComp.as

/**
 * http://blog.flexexamples.com/2008/06/09/setting-a-border-color-on-the-combobox-control-in-flex/
 */
package comps {
    import mx.containers.ApplicationControlBar;
    import mx.containers.Canvas;
    import mx.containers.Form;
    import mx.containers.FormItem;
    import mx.controls.ColorPicker;
    import mx.controls.ComboBox;
    import mx.core.Application;
    import mx.events.ColorPickerEvent;

    public class MyComp extends Canvas {
        private var arr:Array;
        private var appControlBar:ApplicationControlBar;
        private var colorPicker:ColorPicker;
        private var comboBox:ComboBox;

        public function MyComp() {
            super();
            init();
        }

        private function init():void {
            arr = [];
            arr.push({label:"One"});
            arr.push({label:"Two"});
            arr.push({label:"Three"});
            arr.push({label:"Four"});
            arr.push({label:"Five"});
            arr.push({label:"Six"});

            colorPicker = new ColorPicker();
            colorPicker.addEventListener(ColorPickerEvent.CHANGE, colorPicker_change);

            var formItem:FormItem = new FormItem();
            formItem.label = "borderColor:";
            formItem.addChild(colorPicker);

            var form:Form = new Form();
            form.styleName = "plain";
            form.addChild(formItem);

            appControlBar = new ApplicationControlBar();
            appControlBar.dock = true;
            appControlBar.addChild(form);
            Application.application.addChildAt(appControlBar, 0);

            comboBox = new ComboBox();
            comboBox.dataProvider = arr;
            addChild(comboBox);
        }

        private function colorPicker_change(evt:ColorPickerEvent):void {
            comboBox.setStyle("borderColor", evt.color);
        }
    }
}