如何放置WinJS.UI。win splitview内容部分内的菜单?

我有一个非常简单的应用程序。我从VS2015中的WinJS App(Universal Windows)模板开始。我有一个拆分视图,在拆分视图内容部分有一个菜单。单击控制按钮时会显示菜单,但所有选项都不可选。

<div data-win-control="WinJS.UI.SplitView" data-win-options="{closedDisplayMode: 'overlay',panePlacement:'left'}">
    <div class="win-splitview-pane">
    </div>
    <div class="win-splitview-content">
        <button id="selectionButton">Selection</button>
        <div id="selectionMenu" data-win-control="WinJS.UI.Menu">
            <button data-win-options="{label:'Forward',type:'toggle'}" data-win-control="WinJS.UI.MenuCommand"></button>
            <button data-win-options="{label:'Reply',type:'toggle'}" data-win-control="WinJS.UI.MenuCommand"></button>
            <button data-win-options="{label:'Reply All',type:'toggle'}" data-win-control="WinJS.UI.MenuCommand"></button>
        </div>
    </div>
</div>

这方面的JavaScript代码很简单( initSelection 在中调用 app.onactivated 部分):

function initSelection() {
    document.getElementById("selectionButton").addEventListener("click", showFlyout, false);
}
function showFlyout() {
    document.getElementById("selectionMenu").winControl.show(document.getElementById("selectionButton"), "bottom", "left");
}

这可能吗?怎样提前谢谢你。