Responsive web design 学习笔记
Advanced Styling with Responsive Design
此笔记为Coursera同名课程笔记。
Week1
什么是响应式设计?
响应式设计:
- It is designing your sites with multiple screen sizes/resolutions in mind.
- Sites should "work" under any platform, any browser size, any orientation.The user should have the power.
需要考虑的概念 Concepts to consider
- Media queries - decting the viewport size 检测
- Flexible grid-based layout for the relative sizeing
- Flexible images
这里是一个响应式设计网站的范例。
测试网站是否响应式的方法:
- 调整浏览器大小。
- 使用ami.responsivedesign.is帮助判断。
- 使用 Chrome/Firefox Dev Tools。
让网页适应页面大小的三种选项
- Responsive Web Design(RWD) - fluid measurements, flexible grids, and varying CSS rules.同一套代码,通过检测
meta name=viewport
实现。能优化搜索引擎分数。 - Adaptive Design - returns one of multiple versions of a page based on the type of device.根据不同设备返回不同代码。
- Seperate Mobile Site - a seperate page URL for the mobile site.
Why RWD? 响应式页面设计的优点?
- Easier to share your data with a single URL. 容易分享。
- Easier to search engine to index the page. 搜索引擎优化。
- Fewer files = less maintenance. 容易维护。
延伸阅读:Fluid Measurements 动态单位(em、rem、px...)
- Responsive Web Design: Using Fonts Responsibly by Annarita Tranfici
- Web Design Basics: Rem vs. Em vs. PX - Sizing Elements in CSS by Matthew Davis
- What's the Deal with Em and Rem?
- Font Size Idea: px at the Root, rem for Components, em for Text Elements by Chris Coyier
- 综合指南: 何时使用 Em 与 Rem
Fluid Measurements
- Your content should fit the size contraints of the viewport. 要有普适性,不能只适应特定的大小。
- Horizontal scrolling is bad. 避免水平滚动。
Absolute measurements
- px
- 1px 代表显示屏上的一个像素
- mm, cm, in
- 用于打印
- pt
- 1 point = 1/72 of an inch.
- pc
- 1 pica = 12 points.
Relative measurements
- %
- percentage values that are always relative to another value.
- em
- font size of the element.
- rem
- font size of the root element.
- vw
- 1% of viewport width.
- vh
- 1% of viewport height.
1em = 12pt = 16px = 100%
1in = 2.54cm = 25.4mm = 72pt = 12pc
Week 2
Media Queries
- Media queries allow the style to depend upon the meida properties.
- CSS 2.1 used media types.(Just "screen" and "print" option).
CSS3
- CSS 3 increased the capabilities. Style can depend on many features.
- width, height, orientation, resolution, ...
- Boolean operators can also be applied to increase power.(and/or)
The two query components
-
A media type(screen, print, all, ...)
-
The actual query of a media feature and "trigger" size(width, height, orientation, resolution, ...)
example:
screen and (max-device-width: 480px) and (resolution: 163dpi)
How to implement media queries
- Use the @import rule
@import url(smallstyle.css) screen and (min-width:600px) - Put media query directly in the style sheet(Mostly used)
@media screen and (min-width:500px) - Include query in the link (not good)
Wireframes
- Coding after your design.
- Wireframe 可以看作布局的草稿,只关注内容和布局
- Mobile view is the most important view in web design. 移动视图最重要!
- 总的来说就是要提前想好你的页面要怎么根据浏览器大小变化,先设计再动手!
- 一些 Wireframe 的规则
breakpoints
- Size that define a change in your site layout or content.
- Used to provide best possible experience for users based on device infomation.
MOBILE FIRST !!
- You shouldn't see breakpoints for small screens. The default styling already convers that.
- You should have min-width instead of max-width
- 默认设计时,要按照移动视图来进行设计,其次再考虑更大窗口下的展现方式。
Media Queries - Part 2
Step 1: Grab infomation
The meta viewport tag tells mobile browser's viewport how to behave.
<meta name = "viewport" content="width=device-width, initial-scale=1">
BAD practice: 加入maximum-scale=1等限制用户自主选择样式的属性。
Step 2: Fluid layout
BEST practice: use fluid measurement like percentage/em/rem
.
paddings and margins affected by width, not height.
Step 3: Media queries
Fluid layout that is triggered by certain sizes.
ORDERING your rules: default rule always on the top.
Week 3: Framework
Bootstrap 3.0 benefits
- 12-column grid system
- helps with spacing issues
- built-in responsive design
- Common jQuery functionalities
- Accordion, Dorp-down menus, Carousel
- Familiar "look and feel"
- Many sites use Bootstrap
- Makes your forms look "legitimate"
Bootstrap Breakpoints
- Bootstrap hardcodes the breakpoints for different views.
- 部分浏览器不支持小于 300px 的 breakpoint,Bootstrap 支持最小的断点为 320px;
- xs-: minimum width 480px (For most phone)
- sm-: minimum width 768px (Small device and tablets, and smaller window size browser)
- md-: minimum width 992px (Beyond most of phone and tablet)
- lg-: minimum width 1200px
- It it possible to change default value, modify on your need. 默认值可修改,根据需求来
- 不需要知道具体的像素值,只需记住字母对应的含义即可。
Bootstrap Layout System
- Bootstrap layout is based on 12-column grid.
- 3 column = 25%
- 6 column = 50%
- ...
- Every grid consists of:
- A container
- A row
- One or more column classes
- A row
- A container
<div class="container">
<div class="row">
<div class="col-xx-yy">
<!-- xx: viewport size: xs, sm, md, lg -->
<!-- yy: number of columns: 0..12 -->
<!-- These are often combined: -->
<img src="pic.jpg" class="col-xs-12 col-sm-6 col-md-3 col-lg-2">
如果元素是块级元素,无需指定 12 column 的属性。
<div class=“col-xs-12 col-md-3”>Yellow Part</div>
等价于:
<div class=“col-md-3”>Yellow Part</div>
Positioning classes
- On viewports md and up, there is an option for push and pull class.
col-XX-push-YY
=> move YY columns to the
rightcol-XX-pull-YY
=> move YY columns to the
left
Responsive utility classes
hidden-XX
content will only be hidden on the XX screen sizevisible-XX
content will only be visible on the XX screen sizesr-only
content is hidden on all devices except screen readers