Javascript 禁用移动设备上的视差

我在一个有着奇特视差滚动背景的网站上工作，并遵循Mohiuddin Parekh（可用）的教程

这是我的javascript：

$(document).ready(function(){
// Cache the Window object
$window = $(window);

 $('section[data-type="background"]').each(function(){
 var $bgobj = $(this); // assigning the object

  $(window).scroll(function() {

    // Scroll the background at var speed
    // the yPos is a negative value because we're scrolling it UP!                              
    var yPos = -( ($window.scrollTop() - $bgobj.offset().top) / $bgobj.data('speed'));

    // Put together our final background position
    var coords = '50% '+ yPos + 'px';

    // Move the background
    $bgobj.css({ backgroundPosition: coords });

 }); // window scroll Ends

 });    

});

---

这很有效。现在我想做的是，如果使用移动设备（最大宽度：768px）查看站点，则不执行javascript。不幸的是，我不太清楚如何实现这一点，非常感谢您的帮助：）

页面启动时会触发document ready（文档准备就绪），当有人操纵窗口时会调整窗口大小

$( window ).resize(function() {
$window = $(window);
if( $window .width() > 800){

 $('section[data-type="background"]').each(function(){
 var $bgobj = $(this); // assigning the object

  $(window).scroll(function() {

    // Scroll the background at var speed
    // the yPos is a negative value because we're scrolling it UP!                              
    var yPos = -( ($window.scrollTop() - $bgobj.offset().top) / $bgobj.data('speed'));

    // Put together our final background position
    var coords = '50% '+ yPos + 'px';

    // Move the background
    $bgobj.css({ backgroundPosition: coords });

 }); // window scroll Ends

 });    
}
});



$(document).ready(function(){
$window = $(window);
if( $window.width() > 800){
// Cache the Window object

 $('section[data-type="background"]').each(function(){
 var $bgobj = $(this); // assigning the object

  $(window).scroll(function() {

    // Scroll the background at var speed
    // the yPos is a negative value because we're scrolling it UP!                              
    var yPos = -( ($window.scrollTop() - $bgobj.offset().top) / $bgobj.data('speed'));

    // Put together our final background position
    var coords = '50% '+ yPos + 'px';

    // Move the background
    $bgobj.css({ backgroundPosition: coords });

 }); // window scroll Ends

 });    
}
});

---

获取窗口宽度并用if-like-so，if（_-window\u-width>770）{your scroll code}（_-window\u-width是保存$（window.width（））的变量该死，太快了！谢谢：）