移动开发10段常用的JavaScript代码

在开发移动网站过程中，有一些Javascript代码会经常用到。以下是10段常用的JavaScript代码。需要注意的是某几段代码需要jQuery mobile framework支持。

1.如果网页是在iPhone或Android浏览器中查看，则在主体元素中添加“iPhone”或“Android” 类名

if (navigator.userAgent.match(/iPhone/i)) {

	$('body').addClass('iPhone');

} else if (navigator.userAgent.match(/Android/i)) {

         $('body').addClass('Android');

}

iPhone用户浏览示例：

Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A537a Safari/419.3
Mozilla/5.0 (iPhone; U; XXXXX like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A477d Safari/419.3

Android用户浏览示例：

Mozilla/5.0 (Linux; U; Android 2.2; en-us; Nexus One Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1
Mozilla/5.0 (Linux; U; Android 1.6; en-gb; Dell Streak Build/Donut AppleWebKit/528.5+ (KHTML, like Gecko) Version/3.1.2 Mobile Safari/ 525.20.1
Mozilla/5.0 (Linux; U; Android 2.1-update1; de-de; HTC Desire 1.19.161.5 Build/ERE27) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17
Mozilla/5.0 (Linux; U; Android 2.2; en-us; DROID2 GLOBAL Build/S273) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1
Mozilla/5.0 (Linux; U; Android 2.2; en-gb; GT-P1000 Build/FROYO) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1
Mozilla/5.0 (Linux; U; Android 2.1-update1; de-de; E10i Build/2.0.2.A.0.24) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17

2. 移除浏览器地址栏

window.scrollTo(0, 1);

3. 防止网页触摸滚动

notouchmove = function(event) {

	event.preventDefault();

}

<div data-role="page" id="home" ontouchmove="notouchmove(event);">

...

</div>

4. 当横向浏览时显示信息

var updateorientation = function (){

	var classname = '',

	top = 100;

	switch(window.orientation){

		case 0:

		classname += "normal";

		break;



		case -90:

		classname += "landscape";

		break;



		case 90:

		classname += "landscape";

		break;



	}



	if (classname == 'landscape') {

		if ($('#overlay').length === 0) {

			window.scrollTo(0, 1);

			$('body').append('<div id="overlay" style="width: 100%; height:' + $(document).height() + 'px"><span style="top: ' + top + 'px">Landscape view is not supported for this page.</span></div>');

		}

	} else {

		$('#overlay').remove();

	}

};

Usage:



var supportsOrientationChange = "onorientationchange" in window,

orientationEvent = supportsOrientationChange ? "orientationchange" : "resize";



window.addEventListener(orientationEvent, function() {

	updateorientation();

}, false);

5.显示部分描述信息，当点击时显示完整信息

var truncatedesc = function(trunc, len) {

	if (trunc) {

	  var org = trunc;



	  if (trunc.length > len) {

		trunc = trunc.substring(0, len);

		trunc = trunc.replace(/w+$/, '');



		trunc = '<span class="truncated">' + trunc;

		trunc += '<strong class="more-description">...</strong></span>';

		trunc += '<span class="original" style="display: none;">' + org + '</span>';

	  }



	  $('.truncated').live("touchstart touchend", function() {

		$(this).closest('div').find('.original').show();

		$(this).closest('div').find('.truncated').hide();

		return false;

	  });



	  return trunc;

	}

};

Usage:



truncatedesc(item.description, 100);

6. 收到成功的Ajax请求时，重定向到另一个页面(jQuery mobile)

var ajaxurl = ‘http://…’; // Your web service URL



$.ajax({

	url: ajaxurl,

	type: 'GET',

	processData: false,

	contentType: "application/json",

	dataType: "jsonp",

	success: function(data) {

		$.mobile.changePage("results.html");

	},

	error: function() {

		alert('Error!');

	}

});

7. 从列表视图的链接中删除活动状态(jQuery mobile)

$('div').live('pageshow', function (event, ui) {

	$('[data-role=listview] li').removeClass("ui-btn-active");

});

8. 从下拉选择中禁用默认的jQuery mobile样式(jQuery mobile)

$(document).bind("mobileinit", function(){

  	$.mobile.page.prototype.options.keepNative = "select";

});

9. 动态更新列表视图(jQuery mobile)

var output  = '<li><img src="' + item.image + '" alt="' + item.title + '" />';

output += '<h3><a href="' + item.url + '">' + item.title + '</a></h3>';

output += '</li>';	



$('#mylistul').append(output).listview('refresh');

10. 动态添加表单输入和应用默认样式(jQuery mobile)

var html = '<input type="search" name="suburb" id="suburb" placeholder="Enter suburb" />';

$('#searchform').append(html);

$('#suburb').textinput();