TreeSelector繼承于HtmlWidget，其作用主要是處理Tree的Select的功能。
1：具有selectedNode的屬性
2：默認的事件名有：
eventNamesDefault: {
??select : "select",
??destroy : "destroy",
??deselect : "deselect",
??dblselect: "dblselect" // select already selected node.. Edit or whatever
?},
3：注意這段代碼：eventNames的值。
initialize: function() {

??for(name in this.eventNamesDefault) {
???if (dojo.lang.isUndefined(this.eventNames[name])) {
????this.eventNames[name] = this.widgetId+"/"+this.eventNamesDefault[name];
???}
??}

?},
4：監聽樹的事件：
listenTree: function(tree) {
??//標題和圖標的click都綁定到Selector的select事件。
??dojo.event.topic.subscribe(tree.eventNames.titleClick, this, "select");
??dojo.event.topic.subscribe(tree.eventNames.iconClick, this, "select");

??dojo.event.topic.subscribe(tree.eventNames.collapse, this, "onCollapse");
??dojo.event.topic.subscribe(tree.eventNames.moveFrom, this, "onMoveFrom");
??dojo.event.topic.subscribe(tree.eventNames.removeNode, this, "onRemoveNode");
??dojo.event.topic.subscribe(tree.eventNames.treeDestroy, this, "onTreeDestroy");

??/* remember all my trees to deselect when element is movedFrom them */
??this.listenedTrees.push(tree);
?},

5：