我正在使用jquery.parallax-1.1.3.js来获得视差效果。 (网站:http://ianlunn.co.uk/plugins/jquery-parallax/)
问题:它适用于css后台位置。这适用于背景图像,但不适用于我的HTML中的文本。
我想要的:在这个js文件中添加一些代码,允许我对html文本(H1,H2)使用视差效果。我更喜欢带身份证。因此,H1会有一个div,其ID与视差效果相关联。
这是js:
(function( $ ){
var $window = $(window);
var windowHeight = $window.height();
$window.resize(function () {
windowHeight = $window.height();
});
$.fn.parallax = function(xpos, speedFactor, outerHeight) {
var $this = $(this);
var getHeight;
var firstTop;
var paddingTop = 0;
//get the starting position of each element to have parallax applied to it
$this.each(function(){
firstTop = $this.offset().top;
});
if (outerHeight) {
getHeight = function(jqo) {
return jqo.outerHeight(true);
};
} else {
getHeight = function(jqo) {
return jqo.height();
};
}
// setup defaults if arguments aren't specified
if (arguments.length < 1 || xpos === null) xpos = "50%";
if (arguments.length < 2 || speedFactor === null) speedFactor = 0.1;
if (arguments.length < 3 || outerHeight === null) outerHeight = true;
// function to be called whenever the window is scrolled or resized
function update(){
var pos = $window.scrollTop();
$this.each(function(){
var $element = $(this);
var top = $element.offset().top;
var height = getHeight($element);
// Check if totally above or totally below viewport
if (top + height < pos || top > pos + windowHeight) {
return;
}
$this.css('backgroundPosition', xpos + " " + Math.round((firstTop - pos) * speedFactor) + "px");
});
}
$window.bind('scroll', update).resize(update);
update();
};
})(jQuery);
这是如何从html调用js:
<script type="text/javascript" src="js/jquery.parallax-1.1.3.js"></script>
<script type="text/javascript">
$(document).ready(function(){
//.parallax(xPosition, speedFactor, outerHeight) options:
//xPosition - Horizontal position of the element
//inertia - speed to move relative to vertical scroll. Example: 0.1 is one tenth the speed of scrolling, 2 is twice the speed of scrolling
//outerHeight (true/false) - Whether or not jQuery should use it's outerHeight option to determine when a section is in the viewport
$('#third').parallax("50%", 0.5);
})
</script>
你给div一个ID。你给这个Div一个背景图像。您将ID连接到上面的视差效果。我想做同样的事情,但后来用H1。