JQuery.ajax setRequestHeader 添加Authorization

      XMLHttpRequest对象提供了一个设置请求头的方法:setRequestHeader，对应的jQuery可以再beforeSend回调里面设置请求头：

$.ajax({
    type: "GET",
    url: "test.php",
    success: function(data) {
        console.log(data);
    },
    beforeSend: function(xhr) {
       token = window.localStorage.getItem('token');
            xhr.setRequestHeader("Authorization", "Basic " + btoa(token + ":"));
    }
});