flex在美国大学里是什么意思

连线可以用tree的line-alpha属性设置tree.setStyle("lineAlpha",alphaValue);alphaValue从0到1+-号要用图片代替[Embed(source="/assets/plus.gif")];[Embed(source="/assets/minus.gif")];privatefunctionplusDisclosureIconsChange():void{tree.setStyle("disclosureClosedIcon",PLUS);tree.setStyle("disclosureOpenIcon",MINUS);}