flex tree点击事件

var obj:Object = Tree(event.currentTarget).selectedItem;
				if(menuTree.dataDescriptor.isBranch(obj)){
					menuTree.expandItem(obj, !menuTree.isItemOpen(obj),true, true);
				}


<mx:Tree id="menuTree" width="100%" height="100%" dataProvider="{menuData.menuTree}"
						 itemClick="doMenuItemClick(event)"   labelField="@label" styleName="fseTree"></mx:Tree>