Provider Hosted App中使用JOM问题

在使用SharePoint 2013的JOM时，出现以下问题：

ReferenceError: SP is not defined

经反复试验和搜索，得出以下两种方式：

一、直接引用JS文件，引用顺序很重要：

<script type="text/javascript" src="https://nn.sharepoint.com/teams/ap1/gct/_layouts/15/MicrosoftAjax.js"></script>
<script type="text/javascript" src="https://nn.sharepoint.com/teams/ap1/gct/_layouts/15/SP.Runtime.js"></script>
<script type="text/javascript" src="https://nn.sharepoint.com/teams/ap1/gct/_layouts/15/SP.js"></script>
<script type="text/javascript" src="https://nn.sharepoint.com/teams/ap1/gct/_layouts/15/SP.RequestExecutor.js"></script>

<script src="https://nn.sharepoint.com/teams/ap1/gct/SiteAssets/jquery-1.9.1.js"></script>

<script type="text/javascript">
var hostweburl ="https://nn.sharepoint.com/teams/ap1/gct";

$(document).ready(function () {
    var scriptbase = hostweburl + "/_layouts/15/";
    //ExecuteOrDelayUntilScriptLoaded(initializePage, "sp.js");
initializePage();
});

function initializePage()
{
    var context = SP.ClientContext.get_current();
    var user = context.get_web().get_currentUser();

    // This code runs when the DOM is ready and creates a context object which 

is needed to use the SharePoint object model
    $(document).ready(function () {
        getUserName();
    });

    // This function prepares, loads, and then executes a SharePoint query to 

get the current users information
    function getUserName() {
        context.load(user);
        context.executeQueryAsync(onGetUserNameSuccess, onGetUserNameFail);
    }

    // This function is executed if the above call is successful
    // It replaces the contents of the 'message' element with the user name
    function onGetUserNameSuccess() {
        $('#message').text('Hello ' + user.get_title());
    }

    // This function is executed if the above call fails
    function onGetUserNameFail(sender, args) {
        alert('Failed to get user name. Error:' + args.get_message());
    }
}

二、使用Jquery 的$.getScript 方法

<script type="text/javascript">
var hostweburl ="https://nike.sharepoint.com/teams/ap1/gctech";

$(document).ready(function () {
    var scriptbase = hostweburl + "/_layouts/15/";
    var scriptBase = hostweburl + "/_layouts/15/";
$.getScript(scriptBase + "MicrosoftAjax.js").then(function (data) {
    return $.getScript(scriptbase + "SP.Runtime.js");
}).then(function (data) {
    return $.getScript(scriptbase + "SP.js");
}).then(function (data) {
    $.getScript(scriptBase + "SP.RequestExecutor.js");
}).then(function (data) {
    alert("Load as order");
/*
var ctx = new SP.ClientContext(appWebUrl),
        factory = new SP.ProxyWebRequestExecutorFactory(appWebUrl),
        web;

    ctx.set_webRequestExecutorFactory(factory);
    web = ctx.get_web();
    ctx.load(web);
    ctx.executeQueryAsync(function() {
        // log the name of the app web to the console
        console.log(web.get_title());
    }, function(sender, args) {
        console.log("Error : " + args.get_message());
    });
*/
});
</script>