自己做简单自适应宽高 - gpfq

自适应其实就是width，height都随着变化，

但是如果(父级是px固定)兄弟标签是以px为单位，那么再设置div100%就肯定超出范围了(多了兄弟标签px长度),

　　box-sizing方案

1. 外层box-sizing: border-box; 同时设置padding: 100px 0 0；
2. 内层100像素高的元素向上移动100像素，或使用absolute定位防止占据空间；
3. 另一个元素直接<code>height: 100%;

   absolute positioning

   1. 外层position: relative；
   2. 百分百自适应元素直接<code>position: absolute; top: 100px; bottom: 0; left: 0<br><br>我们以body为父级试试不同分辨率效果,我用的方法2,相对来说简单点<br>
      

      <span style="color: #008080;"> 1</span> <span style="color: #0000ff;"><span style="color: #ff00ff;">DOCTYPE html  </span><span style="color: #0000ff;">></span>
      <span style="color: #008080;"> 2</span> <span style="color: #0000ff;"><span style="color: #800000;">html  </span><span style="color: #0000ff;">></span>
      <span style="color: #008080;"> 3</span> <span style="color: #0000ff;"><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;"> 4</span>     <span style="color: #0000ff;"><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>   <span style="color: #0000ff;"></span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;"> 5</span>     <span style="color: #0000ff;"><span style="color: #800000;">meta </span><span style="color: #ff0000;">http-equiv</span><span style="color: #0000ff;">="Content-Type"</span><span style="color: #ff0000;"> content</span><span style="color: #0000ff;">="text/html; charset=utf-8"</span><span style="color: #0000ff;">/></span>
      <span style="color: #008080;"> 6</span>     <span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;"> 7</span> <span style="background-color: #f5f5f5; color: #800000;">        body,html</span><span style="background-color: #f5f5f5; color: #000000;">{</span>
      <span style="color: #008080;"> 8</span> <span style="background-color: #f5f5f5; color: #ff0000;">            padding</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;"> 9</span> <span style="background-color: #f5f5f5; color: #ff0000;">            margin</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">10</span> <span style="background-color: #f5f5f5; color: #ff0000;">            width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">100%</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">11</span> <span style="background-color: #f5f5f5; color: #ff0000;">            height</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">100%</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">12</span> <span style="background-color: #f5f5f5; color: #ff0000;">            font-size</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">20px</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">13</span> <span style="background-color: #f5f5f5; color: #ff0000;">            text-align</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">center</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">14</span>         <span style="background-color: #f5f5f5; color: #000000;">}</span>
      <span style="color: #008080;">15</span> <span style="background-color: #f5f5f5; color: #800000;">         .brother</span><span style="background-color: #f5f5f5; color: #000000;">{</span>
      <span style="color: #008080;">16</span> <span style="background-color: #f5f5f5; color: #ff0000;">             background-color</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#f00</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">17</span> <span style="background-color: #f5f5f5; color: #ff0000;">             width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">100%</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">18</span> <span style="background-color: #f5f5f5; color: #ff0000;">             height</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">70px</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">19</span> <span style="background-color: #f5f5f5; color: #ff0000;">             position</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">absolute</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">20</span>          <span style="background-color: #f5f5f5; color: #000000;">}</span>
      <span style="color: #008080;">21</span> <span style="background-color: #f5f5f5; color: #800000;">        .sister</span><span style="background-color: #f5f5f5; color: #000000;">{</span>
      <span style="color: #008080;">22</span> <span style="background-color: #f5f5f5; color: #ff0000;">            background-color</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#0f0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">23</span> <span style="background-color: #f5f5f5; color: #ff0000;">            width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">140px</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">24</span> <span style="background-color: #f5f5f5; color: #ff0000;">            position</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">absolute</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">25</span> <span style="background-color: #f5f5f5; color: #ff0000;">            top</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">70px</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">26</span> <span style="background-color: #f5f5f5; color: #ff0000;">            bottom</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">27</span>         <span style="background-color: #f5f5f5; color: #000000;">}</span>
      <span style="color: #008080;">28</span> <span style="background-color: #f5f5f5; color: #800000;">        .my</span><span style="background-color: #f5f5f5; color: #000000;">{</span>
      <span style="color: #008080;">29</span> <span style="background-color: #f5f5f5; color: #ff0000;">            position</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">absolute</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">30</span> <span style="background-color: #f5f5f5; color: #ff0000;">            top</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">70px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">top与上边对应-</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
      <span style="color: #008080;">31</span> <span style="background-color: #f5f5f5; color: #ff0000;">            left</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">140px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">left与左边对应-</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
      <span style="color: #008080;">32</span> <span style="background-color: #f5f5f5; color: #ff0000;">            bottom</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">33</span> <span style="background-color: #f5f5f5; color: #ff0000;">            right</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">34</span> <span style="background-color: #f5f5f5; color: #ff0000;">            background-color</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#00f</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
      <span style="color: #008080;">35</span>         <span style="background-color: #f5f5f5; color: #000000;">}</span>
      <span style="color: #008080;">36</span>     <span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">37</span> <span style="color: #0000ff;"></span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">38</span> <span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">39</span> <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="brother"</span><span style="color: #0000ff;">></span>上边高度为PX的div<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">40</span> <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="sister"</span><span style="color: #0000ff;">></span>左边宽度PX的div(高度不要定义)<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">41</span> <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="my"</span><span style="color: #0000ff;">></span>重点div!<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">42</span> <span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
      <span style="color: #008080;">43</span> <span style="color: #0000ff;"></span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span> </span></span></span></span></span></span></span></span></span></span>

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