Windows 8.1: WinJS: appbar won't open/show by default?

I'm working on a Windows 8.1 app and on a data input page I would like the appBar to be open or visible by default as it contains the option to save the data.

http://msdn.microsoft.com/en-us/library/windows/apps/br229676.aspx

I've looked at the link above and tried the show method in the following way:

Markup:

<div id="appbarCommands" data-win-control="WinJS.UI.AppBar" data-win-options="{sticky: 'true'}">
    <button data-win-control="WinJS.UI.AppBarCommand"
            data-win-options="{id:'cmdSaveCustomer', icon:'save', section:'global'}"
            data-win-res="{winControl: {label:'CRM_contactHistory_appBar_SaveLabel', tooltip:'CRM_contactHisory_appBar_SaveToolTip'}}"></button>
</div>

JS Code:

(function () {
        "use strict";

    WinJS.UI.Pages.define("/pages/CRM/customerDetails/contacts/contactHistory/contactHistory.html", {

        ready: function (element, options) {

            WinJS.UI.processAll().done(function () {

                setAppBarState(document.getElementById("appbarCommands"));

            });
            WinJS.Resources.processAll()            
        }
    });
})();

function setAppBarState(appBar) {

    appBar.winControl.show();

}

For whatever reason, the appBar doesn't launch. I've tested it in the appBar sample code and it works fine on there, but it doesn't work in the actual solution.

I wondered if someone could perhaps shed some light on the problem? Or perhaps knows of a reason that would prevent the appbar being shown when the page loads?

Many thanks

Chris

Copyright Notice：Content Author:「Chris Spittles」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/21020060/windows-8-1-winjs-appbar-wont-open-show-by-default