Flex中如何给LineChart设置坐标轴最大最小范围

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        preinitialize="init();" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.charts.chartClasses.IAxis;
            import mx.formatters.CurrencyFormatter;

            private var currFormatter:CurrencyFormatter;

            private function init():void {
                currFormatter = new CurrencyFormatter();
                currFormatter.precision = 2;
            }

            private function linearAxis_labelFunc(item:Object, prevValue:Object, axis:IAxis):String {
                return currFormatter.format(item);
            }

            private function lineChart_creationComplete():void {
                var linearAxisMinimum:int = Math.floor(linearAxis.computedMinimum);
                var linearAxisMaximum:int = Math.ceil(linearAxis.computedMaximum);
                linearAxis.minimum = linearAxisMinimum;
                linearAxis.maximum = linearAxisMaximum;
            }
        ]]>
    </mx:Script>

    <mx:XMLListCollection id="dp">
        <mx:source>
            <mx:XMLList>
                <quote date="8/27/2007" open="40.38" close="40.81" />
                <quote date="8/24/2007" open="40.5" close="40.41" />
                <quote date="8/23/2007" open="40.82" close="40.6" />
                <quote date="8/22/2007" open="40.4" close="40.77" />
                <quote date="8/21/2007" open="40.41" close="40.13" />
                <quote date="8/20/2007" open="40.55" close="40.74" />
                <quote date="8/17/2007" open="40.18" close="40.32" />
                <quote date="8/16/2007" open="39.83" close="39.96" />
                <quote date="8/15/2007" open="40.22" close="40.18" />
                <quote date="8/14/2007" open="41.01" close="40.41" />
                <quote date="8/13/2007" open="41" close="40.83" />
                <quote date="8/10/2007" open="41.3" close="41.06" />
                <quote date="8/9/2007" open="39.9" close="40.75" />
                <quote date="8/8/2007" open="39.61" close="40.23" />
                <quote date="8/7/2007" open="39.08" close="39.42" />
                <quote date="8/6/2007" open="38.71" close="39.38" />
                <quote date="8/3/2007" open="39.47" close="38.75" />
                <quote date="8/2/2007" open="39.4" close="39.52" />
                <quote date="8/1/2007" open="40.29" close="39.58" />
            </mx:XMLList>
        </mx:source>
    </mx:XMLListCollection>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="minimum:">
                <mx:HSlider id="minSlider"
                        minimum="28"
                        maximum="38"
                        value="38"
                        liveDragging="true"
                        snapInterval="1"
                        change="linearAxis.minimum = event.value;" />
            </mx:FormItem>
            <mx:FormItem label="maximum:">
                <mx:HSlider id="maxSlider"
                        minimum="42"
                        maximum="52"
                        value="42"
                        liveDragging="true"
                        snapInterval="1"
                        change="linearAxis.maximum = event.value;" />
            </mx:FormItem>
        </mx:Form>

        <mx:Spacer width="100%" />

        <mx:Legend dataProvider="{lineChart}"
                direction="horizontal" />
    </mx:ApplicationControlBar>

    <mx:LineChart id="lineChart"
            showDataTips="true"
            dataProvider="{dp}"
            width="100%"
            height="100%"
            creationComplete="lineChart_creationComplete();">

        <mx:backgroundElements>
            <mx:GridLines id="gridLines"
                    direction="both"
                    verticalTickAligned="false">
                <mx:verticalStroke>
                    <mx:Stroke color="haloSilver"
                            weight="0"
                            alpha="1.0" />
                </mx:verticalStroke>
                <mx:horizontalStroke>
                    <!-- Set alpha to 0 so stroke isn&apos;t visible. -->
                    <mx:Stroke color="white"
                            weight="0"
                            alpha="0.0" />
                </mx:horizontalStroke>
                <mx:horizontalFill>
                    <mx:SolidColor color="haloSilver"
                            alpha="0.1" />
                </mx:horizontalFill>
            </mx:GridLines>
        </mx:backgroundElements>

        <!-- vertical axis -->
        <mx:verticalAxis>
            <mx:LinearAxis id="linearAxis"
                    baseAtZero="false"
                    title="Price (USD)"
                    minorInterval="0.10"
                    interval="0.5"
                    labelFunction="linearAxis_labelFunc" />
        </mx:verticalAxis>

        <!-- horizontal axis -->
        <mx:horizontalAxis>
            <mx:CategoryAxis id="ca"
                    categoryField="@date"
                    title="Date" />
        </mx:horizontalAxis>

        <!-- horizontal axis renderer -->
        <mx:horizontalAxisRenderers>
            <mx:AxisRenderer axis="{ca}"
                    canDropLabels="true" />
        </mx:horizontalAxisRenderers>

        <!-- series -->
        <mx:series>
            <mx:LineSeries yField="@open"
                    displayName="Open" />
        </mx:series>
    </mx:LineChart>

</mx:Application>