30个经典的jQuery代码开发技巧(2)

jQuery.fn.autoscroll = function(selector) { $('html,body').animate( {scrollTop: $(selector).offset().top}, 500 ); }
//Then to scroll to the class/area you wish to get to like this:
$('.area_name').autoscroll();

20. 检测各种浏览器

复制代码 代码如下:

Detect Safari (if( $.browser.safari)), Detect IE6 and over (if ($.browser.msie && $.browser.version > 6 )), Detect IE6 and below (if ($.browser.msie && $.browser.version <= 6 )), Detect FireFox 2 and above (if ($.browser.mozilla && $.browser.version >= '1.8' ))

21. 替换字符串中的单词

复制代码 代码如下:

var el = $('#id'); el.html(el.html().replace(/word/ig, ''));

22. 关闭右键的菜单

复制代码 代码如下:

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

23. 定义一个定制的选择器

复制代码 代码如下:

$.expr[':'].mycustomselector = function(element, index, meta, stack){
// element- is a DOM element
// index - the current loop index in stack
// meta - meta data about your selector
// stack - stack of all elements to loop
// Return true to include current element
// Return false to explude current element
};
// Custom Selector usage:
$('.someClasses:test').doSomething();

24. 判断一个元素是否存在

复制代码 代码如下:

if ($('#someDiv').length) {
//hooray!!! it exists...
}

25. 使用jQuery判断鼠标的左右键点击

复制代码 代码如下:

$("#someelement").live('click', function(e) { if( (!$.browser.msie && e.button == 0) || ($.browser.msie && e.button == 1) ) { alert("Left Mouse Button Clicked"); } else if(e.button == 2) alert("Right Mouse Button Clicked"); });

26. 显示或者删除输入框的缺省值

复制代码 代码如下:

//This snippet will show you how to keep a default value
//in a text input field for when a user hasn't entered in
//a value to replace it
swap_val = [];
$(".swap").each(function(i){ swap_val[i] = $(this).val();
$(this).focusin(function(){ if ($(this).val() == swap_val[i]) { $(this).val(""); } }).focusout(function(){ if ($.trim($(this).val()) == "") { $(this).val(swap_val[i]); } }); }); <INPUT value="Enter Username here.." type=text>

27. 指定时间后自动隐藏或者关闭元素(1.4支持)

复制代码 代码如下:

//Here's how we used to do it in 1.3.2 using setTimeout
setTimeout(function() { $('.mydiv').hide('blind', {}, 500) }, 5000);
//And here's how you can do it with 1.4 using the delay() feature (this is a lot like sleep)
$(".mydiv").delay(5000).hide('blind', {}, 500);

28. 动态创建元素到DOM

复制代码 代码如下:

var newgbin1Div = $('');
newgbin1Div.attr('id','gbin1.com').appendTo('body');

29. 限制textarea的字符数量

复制代码 代码如下:

jQuery.fn.maxLength = function(max){ this.each(function(){ var type = this.tagName.toLowerCase();
var inputType = this.type? this.type.toLowerCase() : null; if(type == "input" &&
inputType == "text" || inputType == "password"){
//Apply the standard maxLength this.maxLength = max;
} else if(type == "textarea"){ this.onkeypress = function(e){ var ob = e || event;
var keyCode = ob.keyCode;
var hasSelection = document.selection? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;
return !(this.value.length >= max &&
(keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !ob.ctrlKey && !ob.altKey && !hasSelection); };
this.onkeyup = function(){ if(this.value.length > max){ this.value = this.value.substring(0,max); } }; } }); };
//Usage:
$('#gbin1textarea').maxLength(500);

30. 为函数创建一个基本测试用例

复制代码 代码如下:

内容版权声明:除非注明,否则皆为本站原创文章。

转载注明出处:https://www.heiqu.com/wgxsfy.html