使用Win8进行Javascript漫游设置

var test = document.getElementById("TESTButton");
test.addEventListener("click",function () {
     var apPDAta = Windows.Storage.ApplicationData.current;
     var roaR_488_11845@ingSetTings = apPDAta.roaR_488_11845@ingSetTings;

     roaR_488_11845@ingSetTings["test"] = "test";

     var lbl = document.getElementById("testLabel");
     lbl.innerHTML = roaR_488_11845@ingSetTings["test"];
});

我在C#中似乎没有遇到任何问题,但在WinJS中,我只是从读取中得到了Undefined.