10个好用的JQuery代码片段收集

1.预加载图片

(function($) { 
var cache = []; 

// Arguments are image paths relative to the current page. 
$.preLoadImages = function() { 
var args_len = arguments.length; 
for (var i = args_len; i--;) { 
var cacheImage = document.createElement(‘img‘); 
cacheImage.src = arguments[i]; 
cache.push(cacheImage); 
} 
} 
jQuery.preLoadImages("image1.gif", "/path/to/image2.png");

 

2. 让页面中的每个元素都适合在移动设备上展示

var scr = document.createElement(‘script‘); 
scr.setAttribute(‘src‘, ‘https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js‘); 
document.body.appendChild(scr); 
scr.onload = function(){ 
$(‘div‘).attr(‘class‘, ‘‘).attr(‘id‘, ‘‘).css({ 
‘margin‘ : 0, 
‘padding‘ : 0, 
‘width‘: ‘100%‘, 
‘clear‘:‘both‘ 
}); 
};

 

3.图像等比例缩放

$(window).bind("load", function() { 

// IMAGE RESIZE 
$(‘#product_cat_list img‘).each(function() { 
var maxWidth = 120; 
var maxHeight = 120; 
var ratio = 0; 
var width = $(this).width(); 
var height = $(this).height(); 
if(width > maxWidth){ 
ratio = maxWidth / width; 
$(this).css("width", maxWidth); 
$(this).css("height", height * ratio); 
height = height * ratio; 
} 
var width = $(this).width(); 
var height = $(this).height(); 
if(height > maxHeight){ 
ratio = maxHeight / height; 
$(this).css("height", maxHeight); 
$(this).css("width", width * ratio); 
width = width * ratio; 
} 
}); 

//$("#contentpage img").show(); 

// IMAGE RESIZE 
});

 

4.返回页面顶部

// Back To Top 
$(document).ready(function(){ 
$(‘.top‘).click(function() { 
$(document).scrollTo(0,500); 
}); 
}); 
//Create a link defined with the class .top 
<a href="#" class="top">Back To Top</a>

 

5.使用jQuery打造手风琴式的折叠效果

var accordion = { 
init: function(){ 
var $container = $(‘#accordion‘); 
$container.find(‘li:not(:first) .details‘).hide(); 
$container.find(‘li:first‘).addClass(‘active‘); 
$container.on(‘click‘,‘li a‘,function(e){ 
e.preventDefault(); 
var $this = $(this).parents(‘li‘); 
if($this.hasClass(‘active‘)){ 
if($(‘.details‘).is(‘:visible‘)) { 
$this.find(‘.details‘).slideUp(); 
} else { 
$this.find(‘.details‘).slideDown(); 
} 
} else { 
$container.find(‘li.active .details‘).slideUp(); 
$container.find(‘li‘).removeClass(‘active‘); 
$this.addClass(‘active‘); 
$this.find(‘.details‘).slideDown(); 
} 
}); 
} 
}; 

6.通过预加载图片廊中的上一幅下一幅图片来模仿Facebook的图片展示方式

var nextimage = "/images/some-image.jpg"; 
$(document).ready(function(){ 
window.setTimeout(function(){ 
var img = $("").attr("src", nextimage).load(function(){ 
//all done 
}); 
}, 100); 
});

7.使用jQuery和Ajax自动填充选择框

$(function(){ 
$("select#ctlJob").change(function(){ 
$.getJSON("/select.php",{id: $(this).val(), ajax: ‘true‘}, function(j){ 
var options = ‘‘; 
for (var i = 0; i < j.length; i++) { 
options += ‘ 
‘ + j[i].optionDisplay + ‘ 
‘; 
} 
$("select#ctlPerson").html(options); 
}) 
}) 
})

8.自动替换丢失的图片

// Safe Snippet 
$("img").error(function () { 
$(this).unbind("error").attr("src", "missing_image.gif"); 
}); 
// Persistent Snipper 
$("img").error(function () { 
$(this).attr("src", "missing_image.gif"); 
});

9.在鼠标悬停时显示淡入/淡出特效

$(document).ready(function(){ 
$(".thumbs img").fadeTo("slow", 0.6); 
// This sets the opacity of the thumbs to fade down to 60% when the page loads 
$(".thumbs img").hover(function(){ 
$(this).fadeTo("slow", 1.0); 
// This should set the opacity to 100% on hover 
},function(){ 
$(this).fadeTo("slow", 0.6); 
// This should set the opacity back to 60% on mouseout 
}); 
}); 

10.清空表单数据

function clearForm(form) { 

// iterate over all of the inputs for the form 

// element that was passed in 
$(‘:input‘, form).each(function() { 
var type = this.type; 
var tag = this.tagName.toLowerCase(); 
// normalize case 

// it‘s ok to reset the value attr of text inputs, 

// password inputs, and textareas 
if (type == ‘text‘ || type == ‘password‘ || tag == ‘textarea‘) 
this.value = ""; 
// checkboxes and radios need to have their checked state cleared 
// but should *not* have their ‘value‘ changed 
else if (type == ‘checkbox‘ || type == ‘radio‘) 
this.checked = false; 
// select elements need to have their ‘selectedIndex‘ property set to -1 
// (this works for both single and multiple select elements) 
else if (tag == ‘select‘) 
this.selectedIndex = -1; 
}); 
};