您需要连接到_transition事件。

var tabs = dijit.byId("tabs");
dojo.connect(tabs,"_transition", function(newPage, oldPage){
    console.log("I was showing: ", oldPage || "nothing");
    console.log("I am now showing: ", newPage);
});

其中“tabs”是您的标签容器。

下面是一个在Dojo 1.8中工作的完整代码示例，我已经测试过它：

require(["dijit/registry",  "dojo/on", "dojo/ready", "dojo/domReady!"], function (registry, on, ready) {
    ready(function () { //wait till dom is parsed into dijits
        var panel = registry.byId('mainTab');   //get dijit from its source dom element
        on(panel, "Click", function (event) {   //for some reason onClick event doesn't work 
            alert(panel.selectedChildWidget.id);  
        });
    });
});

正确的Dojo 1.7+应该是;

var tabs = registry.byId('someTabs');
tabs.watch("selectedChildWidget", function(name, oval, nval){
    console.log("selected child changed from ", oval, " to ", nval);
});

另一种方式可以是

var tabs = registry.byId('someTabs');
aspect.after(tabs, "selectChild", function (event) {
     console.log("You selected ", tabs.selectedChildWidget.id);
});