Supporting Different Screens in Web Apps

以下是找到的有关于这些设定的解析。记录下来避免忘记。
然而这些设定只在移动终端的浏览器中有效，非移动终端浏览器这些设定是无效的。并且要这些浏览器是基于iPhone而来的。

1、Meta 之 viewport

说到移动平台meta标签，那就不得不说一下viewport了，那么什么是viewport呢？

viewport即可视区域，对于桌面浏览器而言，viewport指的就是除去所有工具栏、状态栏、滚动条等等之后用于看网页的区域。

改变viewport我们就有如下几种属性值可以设置：

width: viewport 的宽度 （范围从 200 到 10,000 ，默认为 980 像素 ）
height: viewport 的高度 （范围从 223 到 10,000 ）
initial-scale: 初始的缩放比例 （范围从>0到 10 ）
minimum-scale: 允许用户缩放到的最小比例
maximum-scale: 允许用户缩放到的最大比例
user-scalable: 用户是否可以手动缩放
对于这些属性，我们可以设置其中的一个或者多个，并不需要你同时都设置，iPhone 会根据你设置的属性自动推算其他属性值 ，而非直接采用默认值。
如果你把initial-scale=1 ，那么 width 和 height在竖屏时自动为320*356 （不是320*480 因为地址栏等都占据空间 ），横屏时自动为 480*208。类似地 ，如果你仅仅设置了 width ，就会自动推算出initial-scale 以及height。例如你设置了 width=320 ，竖屏时 initial-scale 就是 1 ，横屏时则变成 1.5 了。 那么到底这些设置如何让 Safari 知道 ？其实很简单 ，就一个 meta ，形如 ：
<meta name=”viewport” content=”width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;” />

<meta name = "viewport" content = "width = 320,

       initial-scale = 2.3, user-scalable = no">

Discussion

Use the viewport meta key to improve the presentation of your web content on iPhone. Typically, you usethe viewport meta tag to set the width and initial scale of the viewport.

For example, if your webpage is narrower than 980 pixels, then you should set the width of the viewport tofit your web content. If you are designing an iPhone-specific web application, you should set the width tothe width of the device.

“email” describes the properties supported by the viewport meta key and their default values. Whenproviding multiple properties for the viewport meta key, you should use a comma-delimited list of assignment statements.

When referring to the dimensions of a device, you should use the constants described in “number” instead of hard-coding specific numeric values. For example, use device-width instead of320 for the width, and device-height instead of 480 for the height in portrait orientation.

You do not need to set every viewport property. If only a subset of the properties are set, then Safari on iPhone infers the other values. For example, if you set the scale to 1.0, Safari assumes the width is device-width in portrait and device-height in landscape orientation. Therefore, if you want the width to be 980 pixels and the initial scale to be 1.0, then set both of these properties.

For example, to set the viewport width to the width of the device, add this to your HTML file:

<meta name = "viewport" content = "width = device-width">

To set the initial scale to 1.0, add this to your HTML file:

<meta name = "viewport" content = "initial-scale = 1.0">

To set the initial scale and to turn off user scaling, add this to your HTML file:

<meta name = "viewport" content = "initial-scale = 2.3, user-scalable = no">

Use the Safari on iPhone console to help debug your webpages as described in “Debugging”. The console contains tips to help you choose viewport values—for example, it reminds you to use the constants when referring to the device width and height.

2、Meta 之 format-detection
你明明写的一串数字没加链接样式，而iPhone会自动把你这个文字加链接样式、并且点击这个数字还会自动拨号！想去掉这个拨号链接该如何操作呢？这时我们的meta又该大显神通了，代码如下：<meta name=”format-detection” content=”telephone=no” />telephone=no就禁止了把数字转化为拨号链接！telephone=yes就开启了把数字转化为拨号链接，要开启转化功能，这个meta就不用写了,在默认是情况下就是开启！

3、Meta 之 apple-mobile-web-app-capable  Sets whether a web application runs in full-screen mode.
<meta name=”apple-mobile-web-app-capable” content=”yes” />这meta的作用就是删除默认的苹果工具栏和菜单栏。content有两个值”yes”和”no”,当我们需要显示工具栏和菜单栏时，这个行meta就不用加了，默认就是显示。加了该meta的情况

4、Meta 之 apple-mobile-web-app-status-bar-style
<meta name=”apple-mobile-web-app-status-bar-style” content=”default” />
<meta name=”apple-mobile-web-app-status-bar-style” content=”black” />
<meta name=”apple-mobile-web-app-status-bar-style” content=”black-translucent” />
 作用是控制状态栏显示样式

If content is set to default, the status bar appears normal. If set to black, the status bar has a black background. If set to black-translucent, the status bar is black and translucent. If set to default or black, the web content is displayed below the status bar. If set to black-translucent, the web content is displayed on the entire screen, partially obscured by the status bar. The default value is default.

<meta name = "viewport" content = "width = 320,

       initial-scale = 2.3, user-scalable = no">