css画三角形原理解析_莺语_前端开发者

<div id=”div1″></div>
<div id=”div2″></div>
<div id=”div3″></div>
<div id=”div4″></div>
<div id=”div5″></div>
<div id=”div6″></div>

 

<div id=”div1″></div>
<div id=”div2″></div>
<div id=”div3″></div>
<div id=”div4″></div>
<div id=”div5″></div>
<div id=”div6″></div>

 

 

#div1 {
  width: 0; 
  height:0;
  border-right: 40px solid transparent;
  border-left: 40px solid transparent;
  border-bottom:80px solid red
}
#div1 {
  width: 0; 
  height:0;
  border-right: 40px solid transparent;
  border-left: 40px solid transparent;
  border-bottom:80px solid red
}

#div1
width
0
height
0
border-right
40px solid transparent
border-left
40px solid transparent
border-bottom
80px solid red

ps : transparent为设置透明

为了探究css画三角形的原理,先来实验一下,试试单边

#div1 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
}
#div2 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
}
#div3 {
  width: 0; 
  height:0;
  border-bottom: 40px solid ;
}
#div4 {
  width: 0; 
  height:0;
  border-left: 40px solid ;
}
#div1 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
}
#div2 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
}
#div3 {
  width: 0; 
  height:0;
  border-bottom: 40px solid ;
}
#div4 {
  width: 0; 
  height:0;
  border-left: 40px solid ;
}

#div1
width
0
height
0
border-top
40px solid
#div2

width
0
height
0
border-right
40px solid
#div3

width
0
height
0
border-bottom
40px solid
#div4

width
0
height
0
border-left
40px solid

发现没有显示,再来试试两条边

#div1 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-right: 40px solid red;
}
#div2 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-bottom: 40px solid red;
}
#div3 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
}
#div4 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
  border-bottom: 40px solid red;
}
#div5 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
  border-left: 40px solid red;
}
#div6 {
  width: 0; 
  height:0;
  border-bottom: 40px solid ;
  border-left: 40px solid red;
}
#div1 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-right: 40px solid red;
}
#div2 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-bottom: 40px solid red;
}
#div3 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
}
#div4 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
  border-bottom: 40px solid red;
}
#div5 {
  width: 0; 
  height:0;
  border-right: 40px solid ;
  border-left: 40px solid red;
}
#div6 {
  width: 0; 
  height:0;
  border-bottom: 40px solid ;
  border-left: 40px solid red;
}

#div1
width
0
height
0
border-top
40px solid
border-right
40px solid red
#div2

width
0
height
0
border-top
40px solid
border-bottom
40px solid red
#div3

width
0
height
0
border-top
40px solid
border-left
40px solid red
#div4

width
0
height
0
border-right
40px solid
border-bottom
40px solid red
#div5

width
0
height
0
border-right
40px solid
border-left
40px solid red
#div6

width
0
height
0
border-bottom
40px solid
border-left
40px solid red

 发现只有相邻边才会显示,相对边不显示,然后试试三边/四边发现都能显示

为什么设置宽高为0时就会呈三角形?如果设置宽高呢?

#div1 {
  width: 20px; 
  height:20px;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}
#div1 {
  width: 20px; 
  height:20px;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}

#div1
width
20px
height
20px
border-top
40px solid
border-right
40px solid red
border-bottom
40px solid green
border-left
40px solid yellow

为了更清晰的地对比,再来看一看

#div1 {
  width: 20px; 
  height:20px;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}
#div2 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}
#div3 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
  border-bottom: 40px solid green;
}
#div4 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
}
#div1 {
  width: 20px; 
  height:20px;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}
#div2 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-right: 40px solid red;
  border-bottom: 40px solid green;
  border-left: 40px solid yellow;
}
#div3 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
  border-bottom: 40px solid green;
}
#div4 {
  width: 0; 
  height:0;
  border-top: 40px solid ;
  border-left: 40px solid red;
}

#div1
width
20px
height
20px
border-top
40px solid
border-right
40px solid red
border-bottom
40px solid green
border-left
40px solid yellow
#div2

width
0
height
0
border-top
40px solid
border-right
40px solid red
border-bottom
40px solid green
border-left
40px solid yellow
#div3

width
0
height
0
border-top
40px solid
border-left
40px solid red
border-bottom
40px solid green
#div4

width
0
height
0
border-top
40px solid
border-left
40px solid red

从下往上解读:

  1、当宽高为0时,只有两条边,即可以看作朝指定方向缩进、对应宽高的矩形(div4,左上缩进,宽(border-left)40px,,高(border-top)40px),

  2、当宽高为0时,只有三条边,即可看做全部组合的、朝指定方向缩进、对应宽高的矩形

  ( div3,[左上缩进,宽(border-left)40px,,高(border-top)40px],[左下缩进,宽(border-left)40px,,高(border-bottom)40px],[上下缩进,对应边不显示] ),靠左拼接

  3、当宽高为0时,有四条边,即可看做全部组合的、朝指定方向缩进、对应宽高的矩形

  ( div2,{ [左上缩进,不再重复……],[右上缩进,……] 靠上拼接},{ [右上缩进,……],[右下缩进,……] 靠右拼接},{ [右下缩进,……],[左下缩进,……] 靠下拼接},{ [左下缩进,不再重复……],[左上缩进,……] 靠左拼接} ) 

   4、当宽高不为0时,根据盒子模型,border在外围,会被元素撑开

» 本文来自:前端开发者 » 《css画三角形原理解析_莺语_前端开发者》
» 本文链接地址:https://www.rokub.com/73569.html
» 您也可以订阅本站:https://www.rokub.com
赞(0)
64K

评论 抢沙发

评论前必须登录!