Limiting the number of characters a user can type into a NumericStepper control’s text input field in Flex

The following example shows how you can limit the number of characters a user can type into a Flex NumericStepper control by setting the maxChars property.

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/05/19/limiting-the-number-of-characters-a-user-can-type-into-a-numericstepper-controls-text-input-field-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="maxChars:">
                <mx:HSlider id="slider"
                        minimum="1"
                        maximum="3"
                        snapInterval="1"
                        tickInterval="1"
                        liveDragging="true" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:NumericStepper id="numericStepper"
            minimum="0"
            maximum="10000"
            stepSize="10"
            maxChars="{slider.value}" />

</mx:Application>

View source is enabled in the following example.

Setting the maxChars property only limits the number of characters that can be typed. If your maxChars property was 2 and the NumericStepper control’s maximum property was 1000, the user could still enter numbers between 100 and 1000 using the Home/End keys, up/down arrows on the keyboard, or the up/down buttons in the NumericStepper control.