SVG XML 格式定义图形入门介绍

SVG

SVG means Scalable Vector Graphics.

• SVG 使用 XML 格式定义图形
• SVG 图像在放大或改变尺寸的情况下其图形质量不会有所损失
• SVG 是万维网联盟的标准

Hello World

• Use SVG in html

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
    <circle cx="100" cy="50" r="40" fill="#0099FF"/>
</svg>

</sh>

and you can see:

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<circle cx="100" cy="50" r="40" fill="#0099FF"/>
</svg>

• Link to the SVG file
  You can use <a> tag to link to the svg file, like this:

<a href="rect.svg">rect.svg</a>

rect.svg

Shape

There some pre-shapes:

• 矩形 <rect>
• 圆形 <circle>
• 椭圆 <ellipse>
• 线 <line>
• 折线 <polyline>
• 多边形 <polygon>
• 路径 <path>

Rect

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
    <rect x="50" y="20" rx="20" ry="20" width="150" height="150"
      style="fill:#0099FF;stroke:black;stroke-width:1;opacity:0.5"/>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">

<rect x="50" y="20" rx="20" ry="20" width="150" height="150"
  style="fill:#0099FF;stroke:black;stroke-width:1;opacity:0.5"/>

</svg>

Line

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
    <line x1="20" y1="20" x2="140" y2="80" style="stroke:#A020F0;stroke-width:3;"/>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">

<line x1="20" y1="20" x2="140" y2="80" style="stroke:#A020F0;stroke-width:3;"/>

</svg>

Polygon

the fill-rule

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <polygon points="100,10 40,180 190,60 10,60 160,180"
  style="fill:#FAF0E6;stroke:gold;stroke-width:2;fill-rule:nonzero;" />
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<polygon points="100,10 40,180 190,60 10,60 160,180"
style="fill:#FAF0E6;stroke:gold;stroke-width:2;fill-rule:nonzero;" />
</svg>

Polyline

<sh class="xml">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<polyline points="0,40 40,40 40,80 80,80 80,120 120,120 120,140"
style="fill:white;stroke:#DA70D6;stroke-width:2"/>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<polyline points="0,40 40,40 40,80 80,80 80,120 120,120 120,140"
style="fill:white;stroke:#DA70D6;stroke-width:2"/>
</svg>

Path

Some Commands

所有命令均允许小写字母。大写表示绝对定位，小写表示相对定位

M = moveto
L = lineto
H = horizontal lineto
V = vertical lineto
C = curveto
S = smooth curveto
Q = quadratic Bézier curve
T = smooth quadratic Bézier curveto
A = elliptical Arc
Z = closepath

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <path d="M150 0 L75 160 L225 160 Z"/>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<path d="M150 0 L75 160 L225 160 Z"/>
</svg>

Text

text zh_CN

• Common text

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <text x="100" y="15" fill="#666666">Hello SVG</text>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<text x="100" y="15" fill="#666666">Hello SVG</text>
</svg>

• Rotate

rotate(<rotate-angle> [<cx> <cy>])

<sh class="xml">

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <text x="100" y="15" fill="#666666" rotate="46 10,10" >Hello SVG</text>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<text x="100" y="15" fill="#666666" transform="rotate(46 20,40)">Hello SVG</text>
</svg>

• Text with path

<sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
   <defs>
    <path id="path1" d="M75,20 a1,1 0 0,0 100,0" />
  </defs>
  <text x="10" y="100" style="fill:grey;">
    <textPath xlink:href="#path1">I love SVG I love SVG</textPath>
  </text>
</svg>

</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>

<path id="path1" d="M75,20 a1,1 0 0,0 100,0" />

</defs>
<text x="10" y="100" style="fill:grey;">

<textPath xlink:href="#path1">I love SVG I love SVG</textPath>

</text>
</svg>

• <tspan>

元素可以安排任何分小组与<tspan>元素的数量

<sh>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<text x="10" y="20" style="fill:grey;">Several lines:

<tspan x="10" y="45">First line</tspan>
<tspan x="20" y="70">Second line</tspan>

</text>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<text x="10" y="20" style="fill:grey;">Several lines:

<tspan x="10" y="45">First line</tspan>
<tspan x="20" y="70">Second line</tspan>

</text>
</svg>

Stroke

• Stroke 属性定义一条线，文本或元素轮廓颜色

g元素这样的将多个元素组织在一起的元素

<sh>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none">

<path stroke="red" d="M5 20 l215 0" />
<path stroke="blue" d="M5 40 l215 0" />
<path stroke="black" d="M5 60 l215 0" />

</g>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none">

<path stroke="red" d="M5 20 l215 0" />
<path stroke="blue" d="M5 40 l215 0" />
<path stroke="black" d="M5 60 l215 0" />

</g>
</svg>

• stroke-width 属性定义了一条线，文本或元素轮廓厚度

<sh>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey">

  <path stroke-width="2" d="M5 20 l215 0" />
  <path stroke-width="6" d="M5 40 l215 0" />
  <path stroke-width="3" d="M5 60 l215 0" />

</g>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey">

<path stroke-width="2" d="M5 20 l215 0" />
<path stroke-width="6" d="M5 40 l215 0" />
<path stroke-width="3" d="M5 60 l215 0" />

</g>
</svg>

• stroke-linecap 属性定义不同类型的开放路径的终结

<sh>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey" stroke-width="4">

  <path stroke-linecap="round" d="M5 20 l215 0" />
  <path stroke-linecap="butt" d="M5 40 l215 0" />
  <path stroke-linecap="square" d="M5 60 l215 0" />

</g>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey" stroke-width="7">

  <path stroke-linecap="round" d="M5 20 l215 0" />
  <path stroke-linecap="butt" d="M5 40 l215 0" />
  <path stroke-linecap="square" d="M5 60 l215 0" />

</g>
</svg>

• stroke-dasharray 创建不同的虚线

<sh>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey" stroke-width="4">

<path stroke-dasharray="5,5" d="M5 20 l215 0" />
<path stroke-dasharray="10,10" d="M5 40 l215 0" />
<path stroke-dasharray="20,10,5,5,5,10" d="M5 60 l215 0" />

</g>
</svg>
</sh>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
<g fill="none" stroke="grey" stroke-width="4">

<path stroke-dasharray="5,5" d="M5 20 l215 0" />
<path stroke-dasharray="10,10" d="M5 40 l215 0" />
<path stroke-dasharray="20,10,5,5,5,10" d="M5 60 l215 0" />

</g>
</svg>