javascript - 在移动设备上禁用视差

Question

我正在开发一个具有精美视差滚动背景的网站，并遵循 Mohiuddin Parekh 的教程(可用 here )

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

 });    

});

这很好用。现在我想做的是，如果使用移动设备(最大宽度:768px)查看网站，则不执行 JavaScript。不幸的是，我不太确定如何实现这一点，感谢任何帮助:)

Answer 1

页面启动时触发文档就绪，并且当有人操作窗口时触发窗口大小

$( 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

 });    
}
});