【实用】需要收藏备用的JQuery代码片段

1 元素屏幕居中

jQuery.fn.center = function () {
this.css("position","absolute");
this.css("top",($(window).height()-this.height())/2+$(window).scrollTop()+"px");
this.css("left",($(window).width()-this.width())/2+$(window).scrollLeft()+"px");
return this;
}
$("#myDiv").center();

2 获取页面路径相关参数

//值：http://42du.cn/list#jq
var url = document.URL;
//值：http:
var protocol = location.protocol;
//值：42du.cn
var host = location.host;
//值：jq
var hashP = document.URL.split('#')[1];

3 删除内联样式

$("*[style]").attr("style", "");

4 长度限制并截取

var $elem = $("#title");
if($elem.text().length > 30) {
$elem.text($elem.text().substr(0, 27)+"...");
}

5 外链新窗口打开

$("a[@href^='http']").attr('target','_blank');

6 测试JQuery与其它库冲突情况

//测试冲突代码
$("#jqtest").click( function() {
alert("jQuery is working!");
});
//避免冲突
var $jq = jQuery.noConflict();
$jq("#jqtest").click( function() {
alert("jQuery is working!");
});

7 加载JQuery即使CDN掉线

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>window.jQuery || document.write('<script src="/media/js/jquery.js"><\/script>')</script>

8 加载遮罩层，点击移除

$('<div id="overlay"></div>')
.css({
position    : 'fixed',
top         : 0,
left        : 0,
right       : 0,
bottom      : 0,
opacity     : 0.6,
background  : 'black',
display     : 'none'
})
.appendTo('body')
.fadeIn('normal')
.click(function () {
$(this).fadeOut('normal', function () {
$(this).remove();
})
});

9 元素固顶

//注意调整边界值
$(window).scroll(function() {
if ($(window).scrollTop() > 100) {
$('#navbar').css({'position' : 'fixed', 'top' : 0});
} else {
$('#navbar').css({'position' : 'relative', 'top' : 'none'});
}
});

10 禁止右键菜单

$(document).bind('contextmenu', function () {
return false;
})

11 对象插件模版代码

(function($){
var MyPlugin = function(element, options) {
var elem = $(element);
var obj = this;
var settings = $.extend({param: 'defaultValue'}, options || {});
// 公有方法
this.publicMethod = function(){
console.log('public method called!');
};
// 私有方法
var privateMethod = function() {
console.log('private method called!');
};
};
$.fn.myplugin = function(options) {
return this.each(function(){
var element = $(this);
// Return early if this element already has a plugin instance
if (element.data('myplugin')) return;
// pass options to plugin constructor
var myplugin = new MyPlugin(this, options);
// Store plugin object in this element's data
element.data('myplugin', myplugin);
});
};
})(jQuery);

12 延伸阅读