Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/11/29/creating-a-flex-tree-control-with-variable-row-heights/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:XML id="xmlDP">
        <root>
            <para label="Paragraph 1">
                <node label="Lorem ipsum dolor sit amet, consectetuer adipiscing elit." />
                <node label="Cras porttitor nunc a pede." />
                <node label="Nulla ac magna non risus accumsan egestas." />
                <node label="Aenean pretium porta felis." />
                <node label="Sed massa." />
            </para>
            <para label="Paragraph 2">
                <node label="Pellentesque pretium eros id odio tincidunt lobortis." />
                <node label="Praesent vitae dolor eget nisl adipiscing pretium." />
                <node label="Fusce nonummy dignissim risus." />
                <node label="Nunc sodales, lectus vitae nonummy cursus, augue lectus auctor orci, vel aliquet enim neque vel eros." />
                <node label="Donec laoreet euismod libero." />
                <node label="Etiam ut lectus." />
            </para>
            <para label="Paragraph 3">
                <node label="Maecenas ut nibh eu diam viverra suscipit." />
                <node label="Pellentesque auctor, turpis vel lobortis suscipit, neque tortor tristique nibh, venenatis suscipit nisl nisl eget magna." />
                <node label="Donec interdum." />
                <node label="Praesent diam." />
            </para>
            <para label="Paragraph 4">
                <node label="Proin nulla." />
                <node label="Morbi tincidunt, sapien in sollicitudin venenatis, nibh tortor pretium ante, non pharetra urna dolor et libero." />
                <node label="In malesuada risus at neque." />
            </para>
        </root>
    </mx:XML>

    <mx:Tree id="tree"
            dataProvider="{xmlDP}"
            labelField="@label"
            showRoot="false"
            variableRowHeight="true"
            wordWrap="true"
            alternatingItemColors="[#FFFFFF,#EEEEEE]"
            showScrollTips="true"
            width="300"
            rowCount="6" />

</mx:Application>

View source is enabled in the following example.

 

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/27/creating-multi-line-list-rows-with-variable-row-heights/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        creationComplete="init();">

    <mx:Script>
        <![CDATA[
            import mx.rpc.events.FaultEvent;
            import mx.rpc.events.ResultEvent;

            private function init():void {
                commentsXML.send();
            }

            private function commentsXML_result(evt:ResultEvent):void {
                var resultXML:XML = evt.currentTarget.lastResult;
                list.dataProvider = resultXML.channel.item;
            }

            private function commentsXML_fault(evt:FaultEvent):void {
                mx.controls.Alert.show("Unable to load XML:\n" + commentsXML.url, "ERROR");
            }
        ]]>
    </mx:Script>

    <mx:HTTPService id="commentsXML"
            url="http://blog.flexexamples.com/comments/feed/"
            resultFormat="e4x"
            showBusyCursor="true"
            result="commentsXML_result(event);"
            fault="commentsXML_fault(event);" />

    <mx:List id="list"
            variableRowHeight="true"
            wordWrap="true"
            labelField="title"
            width="250" />

</mx:Application>

View source is enabled in the following example.