<svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 矩形 -->
  <rect x="10" y="10" width="30" height="30" stroke="black" fill="transparent" stroke-width="5"/>
  <!-- 圆角矩形 -->
  <rect x="60" y="10" rx="10" ry="10" width="30" height="30" stroke="black" fill="transparent" stroke-width="5"/>
</svg>

<svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 圆形 -->
  <circle cx="25" cy="25" r="20" stroke="red" fill="transparent" stroke-width="5"/>
  <!-- 椭圆形 -->
  <ellipse cx="75" cy="25" rx="20" ry="5" stroke="red" fill="transparent" stroke-width="5"/>
</svg>

<svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 直线 -->
  <line x1="10" x2="90" y1="10" y2="45" stroke="orange" fill="transparent" stroke-width="5"/>
  <!-- 折线 -->
  <polyline points="10,25 20,25 30,55 50,45 60, 65 70,75 80,65 90,80"
      stroke="blue" fill="transparent" stroke-width="5"/>
</svg>

<svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 多边形 -->
  <polygon points="50,10 55,30 70,30 60,40 65,55 50,45 35,55 40,40 30,30 45,30"
      stroke="green" fill="transparent" stroke-width="5"/>
</svg>

<svg width="100px" height="100px" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 画笔起点在 (10, 10) 处，然后绘制一个矩形 -->
  <path stroke="green" fill="transparent" stroke-width="5" d="M10,10 H 90 V 90 H 10 L10,10"/>
</svg>

<svg width="100px" height="100px" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 最后使用 Z 闭合命令简化 path 元素 -->
  <path d="M10,10 H 90 V 90 H 10 Z" fill="transparent" stroke="black"/>
</svg>

<svg width="100px" height="100px" version="1.1" xmlns="http://www.w3.org/2000/svg">
  <!-- 使用相对坐标绘制一个 80 * 80 的正方形 -->
  <!-- 画笔移动到(10,10)点，由此开始，向右移动 80 像素构成一条水平线，然后向下移动 80 像素，然后向左移动 80 像素，然后再回到起点 -->
    <path d="M10,10 h 80 v 80 h -80 Z" fill="transparent" stroke="black"/>
</svg>

<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <!-- A link around a shape -->
  <a href="/docs/Web/SVG/Element/circle">
    <circle cx="50" cy="40" r="35"/>
  </a>
  <!-- A link around a text -->
  <a href="/docs/Web/SVG/Element/text">
    <text x="50" y="90" text-anchor="middle">
      &lt;circle&gt;
    </text>
  </a>
</svg>

/* As SVG does not provide a default visual style for links,
   it's considered best practice to add some */
@namespace svg url(http://www.w3.org/2000/svg);
/* Necessary to select only SVG <a> elements, and not also HTML’s.
   See warning below */
svg|a:link, svg|a:visited {
  cursor: pointer;
}
svg|a text,
text svg|a {
  fill: blue; /* Even for text, SVG uses fill over color */
  text-decoration: underline;
}
svg|a:hover, svg|a:active {
  outline: dotted 1px blue;
}

<svg style="width: 200px; height:200px" viewBox="0 0 10 10" xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink">
  <!-- Some graphical objects to use -->
  <defs>
    <circle id="myCircle" cx="0" cy="0" r="5" />
    <linearGradient id="myGradient" gradientTransform="rotate(90)">
      <stop offset="20%" stop-color="gold" />
      <stop offset="90%" stop-color="red" />
    </linearGradient>
  </defs>
  <!-- using my graphical objects -->
  <use x="5" y="5" xlink:href="#myCircle" fill="url('#myGradient')" />
</svg>

<svg style="width: 200px; height:200px" viewBox="0 0 30 10" xmlns="http://www.w3.org/2000/svg">
  <circle id="myCircle" cx="5" cy="5" r="4" stroke="blue"/>
  <use href="#myCircle" x="10" fill="blue"/>
  <use href="#myCircle" x="20" fill="white" stroke="red"/>
  <!-- stroke="red" will be ignored here, as stroke was already set on myCircle. Most attributes (except for x, y, width, height and (xlink:)href) do not override those set in the ancestor. That's why the circles have different x positions, but the same stroke value. -->
</svg>

<svg width="230" height="120" xmlns="http://www.w3.org/2000/svg">
  <filter id="blurMe">
    <!-- 高斯模糊效果 -->
    <feGaussianBlur stdDeviation="5"/>
  </filter>
  <circle cx="60" cy="60" r="50" fill="green"/>
  <!-- 应用滤镜 blurMe -->
  <circle cx="170" cy="60" r="50" fill="green" filter="url(#blurMe)"/>
</svg>

<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
  <polygon points="5,5 195,10 185,185 10,195" />
  <!-- Common use case: embed HTML text into SVG -->
  <foreignObject x="20" y="20" width="160" height="160">
    <!--
      In the context of SVG embeded into HTML, the XHTML namespace could
      be avoided, but it is mandatory in the context of an SVG document
    -->
    <div xmlns="http://www.w3.org/1999/xhtml">
      Lorem ipsum dolor sit amet, consectetur adipiscing elit.
      Sed mollis mollis mi ut ultricies. Nullam magna ipsum,
      porta vel dui convallis, rutrum imperdiet eros. Aliquam
      erat volutpat.
    </div>
  </foreignObject>
</svg>

<svg width="200" height="200" style="border: 1px blue solid" viewBox="0 0 15 15" xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink">
  <defs>
    <linearGradient id="myLinearGradient" gradientTransform="rotate(90)">
      <stop offset="5%"  stop-color="gold" />
      <stop offset="95%" stop-color="red" />
    </linearGradient>
    <radialGradient id="myRadialGradient">
      <stop offset="10%" stop-color="gold" />
      <stop offset="95%" stop-color="red" />
    </radialGradient>
  </defs>
  <!-- using my linear gradient -->
  <circle cx="5" cy="5" r="2" fill="url('#myLinearGradient')" />
  <!-- using my radial gradient -->
  <circle cx="10" cy="5" r="2" fill="url('#myRadialGradient')" />
</svg>

<svg width="200" height="200" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <defs>
    <!-- arrowhead marker definition -->
    <marker id="arrow" viewBox="0 0 10 10" refX="5" refY="5"
        markerWidth="6" markerHeight="6"
        orient="auto-start-reverse">
      <path d="M 0 0 L 10 5 L 0 10 z" />
    </marker>
    <!-- simple dot marker definition -->
    <marker id="dot" viewBox="0 0 10 10" refX="5" refY="5"
        markerWidth="5" markerHeight="5">
      <circle cx="5" cy="5" r="5" fill="red" />
    </marker>
  </defs>
  <!-- Coordinate axes with a arrowhead in both direction -->
  <polyline points="10,10 10,90 90,90" fill="none" stroke="black"
   marker-start="url(#arrow)" marker-end="url(#arrow)"  />
  <!-- Data line with polymarkers -->
  <polyline points="15,80 29,50 43,60 57,30 71,40 85,15" fill="none" stroke="blue"
   marker-start="url(#dot)" marker-mid="url(#dot)"  marker-end="url(#dot)" />
</svg>

<svg width="200" height="200" viewBox="0 0 10 10" xmlns="http://www.w3.org/2000/svg">
  <script>
  // <![CDATA[
  window.addEventListener('DOMContentLoaded', () => {
    function getColor () {
      const R = Math.round(Math.random() * 255).toString(16).padStart(2,'0')
      const G = Math.round(Math.random() * 255).toString(16).padStart(2,'0')
      const B = Math.round(Math.random() * 255).toString(16).padStart(2,'0')
      return `#${R}${G}${B}`
    }
    document.querySelector('circle').addEventListener('click', (e) => {
      e.target.style.fill = getColor()
    })
  })
  // ]]>
  </script>
  <circle cx="5" cy="5" r="4" />
</svg>

<svg width="200" height="200" viewBox="0 0 50 50" xmlns="http://www.w3.org/2000/svg">
  <circle cx="25" cy="25" r="20" fill="blue">
    <!-- 在点击时触发属性 r 修改，修改为 25，持续 500ms 后恢复原值 -->
    <set attributeName="r" to="25" begin="click" dur="500ms" />
  </circle>
</svg>

<svg width="200" height="200" viewBox="0 0 10 10" xmlns="http://www.w3.org/2000/svg">
  <style>
    circle {
      fill: gold;
      stroke: maroon;
      stroke-width: 2px;
    }
  </style>
  <circle cx="5" cy="5" r="4" />
</svg>

<svg width="300" height="300" viewBox="0 0 300 100" xmlns="http://www.w3.org/2000/svg" stroke="red" fill="grey">
  <circle cx="50" cy="50" r="40" />
  <circle cx="150" cy="50" r="4" />
  <svg viewBox="0 0 10 10" x="200" width="100">
    <circle cx="5" cy="5" r="4" />
  </svg>
</svg>

<svg viewBox="0 -20 100 50">
   <switch>
      <text systemLanguage="ar">مرحبا</text>
      <text systemLanguage="de,nl">Hallo!</text>
      <text systemLanguage="zh-Hans">你好!</text>
      <text systemLanguage="en-us">Howdy!</text>
      <text systemLanguage="en-gb">Wotcha!</text>
      <text systemLanguage="en-au">G'day!</text>
      <text systemLanguage="en">Hello!</text>
      <text systemLanguage="es">Hola!</text>
      <text systemLanguage="fr">Bonjour!</text>
      <text systemLanguage="ja">こんにちは</text>
      <text systemLanguage="ru">Привет!</text>
      <text>☺</text>
   </switch>
</svg>

<svg width="200" height="200" viewBox="0 0 80 20" xmlns="http://www.w3.org/2000/svg">
  <!-- Our symbol in its own coordinate system -->
  <symbol id="myDot" width="10" height="10" viewBox="0 0 2 2">
    <circle cx="1" cy="1" r="1" />
  </symbol>
   <!-- A grid to materialize our symbol positioning -->
  <path d="M0,10 h80 M10,0 v20 M25,0 v20 M40,0 v20 M55,0 v20 M70,0 v20" fill="none" stroke="pink" />
  <!-- All instances of our symbol -->
  <use href="#myDot" x="5"  y="5" style="opacity:1.0" />
  <use href="#myDot" x="20" y="5" style="opacity:0.8" />
</svg>