在其他地方你学不到的jQuery小贴士和技巧(欢迎收

下面小编给大家整理了8个技巧对程序员来说非常的有帮助,具体如下所示:

1) 禁用鼠标右键单击

  jQuery程序员可以使用此代码在网页上禁用鼠标右键点击。

$(document).ready(function() { //catch the right-click context menu $(document).bind("contextmenu",function(e) { //warning prompt - optional alert("No right-clicking!"); //delete the default context menu return false; }); });

2) 利用jQuery调整文字大小

使用此代码,用户可以重新网站上文字的大小(增大和减少)

$(document).ready(function() { //find the current font size var originalFontSize = $('html').css('font-size'); //Increase the text size $(".increaseFont").click(function() { var currentFontSize = $('html').css('font-size'); var currentFontSizeNumber = parseFloat(currentFontSize, 10); var newFontSize = currentFontSizeNumber*1.2; $('html').css('font-size', newFontSize); return false; }); //Decrease the Text Size $(".decreaseFont").click(function() { var currentFontSize = $('html').css('font-size'); var currentFontSizeNum = parseFloat(currentFontSize, 10); var newFontSize = currentFontSizeNum*0.8; $('html').css('font-size', newFontSize); return false; }); // Reset Font Size $(".resetFont").click(function(){ $('html').css('font-size', originalFontSize); }); });

3) 在新的Windows打开链接

  Try this code and increase your site impressions because using this jquery code users will go on new window after clicking on any link of your site. Code is below: -

$(document).ready(function() { //select all anchor tags that have http in the href //and apply the target=_blank $("a[href^='http']").attr('target','_blank'); });

4) Style Sheets Swap

  Swap style sheets using this code and the “Style sheets swap” script is below: -

$(document).ready(function() { $("a.cssSwap").click(function() { //swap the link rel attribute with the value in the rel $('link[rel=stylesheet]').attr('href' , $(this).attr('rel')); }); });

5) 回到顶部链接

  That is very common function you can see on eve site nowadays is ” Back to Top”. This functionality is very useful for long pages for make short in a single click. Visit this code below: -

$(document).ready(function() { //when the link is clicked $('#top').click(function() { //scoll the page back to the top $(document).scrollTo(0,500); } });

6) 获取鼠标光标的x和y轴

  You can find the values of X and Y coordinator of mouse pointer. Code is blow : -

$().mousemove(function(e){ //display the x and y axis values inside the P element $('p').html("X Axis : " + e.pageX + " | Y Axis " + e.pageY); });

7) 检测当前鼠标坐标

  使用这个脚本,你可以在jQuery所支持的任何Web浏览器找到当前鼠标的坐标。代码如下:

$(document).ready(function() { $().mousemove(function(e) { $('# MouseCoordinates ').html("X Axis Position = " + e.pageX + " and Y Axis Position = " + e.pageY); }); });

8) 在jQuery中预加载图片

  此图像预加载的脚本有助于非常快速加载图像或网页。你不必等待图像加载。代码:

jQuery.preloadImagesInWebPage = function() { for(var ctr = 0; ctr<arguments.length; ctr++) { jQuery("<img alt="">").attr("src", arguments[ctr]); } } To use the above method, you can use the following piece of code: $.preloadImages("image1.gif", "image2.gif", "image3.gif"); To check whether an image has been loaded, you can use the following piece of code: $('#imageObject').attr('src', 'image1.gif').load(function() { alert('The image has been loaded…'); });

做好如下工作保你jQuery的性能大提升

1. Append Outside of Loops

凡是触及到DOM都是有代价的。如果你向DOM当中附加大量的元素,你会想一次性将它们全部附加进来,而不是分多次进行。当在循环当中附加元素就会产生一个常见的问题。

$.each( myArray, function( i, item ) { var newListItem = "<li>" + item + "</li>"; $( "#ballers" ).append( newListItem ); });

一个常用的技巧是利用文档片段(document fragment)。在循环的每一次迭代当中,将元素附加到片段而不是DOM元素当中。当循环结束后,将片段附加到DOM元素当中即可。

var frag = document.createDocumentFragment(); $.each( myArray, function( i, item ) { var newListItem = document.createElement( "li" ); var itemText = document.createTextNode( item ); newListItem.appendChild( itemText ); frag.appendChild( newListItem ); }); $( "#ballers" )[ ].appendChild( frag );

另一个简单的技巧是在循环的每次迭代当中,持续构建一个字符串。当循环结束后,将DOM元素的HTML设置成该字符串。

var myHtml = ""; $.each( myArray, function( i, item ) { myHtml += "<li>" + item + "</li>"; }); $( "#ballers" ).html( myHtml );

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