How to code an arrow using css

问题

Hi guys I'm trying to code an arrow like this in css, I'e viewed examples on codepen, but now I'm thinking whether it is actually possible?

回答1:

For arrow and lines i have use border

.content {
  margin-top: 30px;
  position: relative;
  border: 2px solid black;
  border-bottom: 2px;
  border-radius: 5px;
  width: 200px;
  height: 40px;
}

.content:before,
.content:after,
.center:before {
  content: '';
  width: 0;
  height: 0;
  border-width: 8px 8px;
  border-color: #000 transparent transparent transparent;
  border-style: solid;
  position: absolute;
}

.content:before {
  left: -8px;
  top: 36px;
}

.content:after {
  right: -8px;
  top: 36px;
}

.center:before {
  right: -8px;
  top: 60px;
}

.center {
  position: absolute;
  height: 60px;
  top: -24px;
  left: 50%;
  margin-left:-2px;
  border: 1px solid black;
}

<div class="content">
  <div class="center">
  </div>
</div>

回答2:

Here is another trick using only one element and multiple linear-gradient as background and you can adjust the size/position of each arrow individually:

.arrows {
  width:300px;
  height:100px;
  position:relative;
  background:
  /* For the 3 lines*/
  linear-gradient(#000,#000) 10px 25px/2px calc(100% - 30px),
  linear-gradient(#000,#000) 50% 0/2px calc(100% - 2px),
  linear-gradient(#000,#000) calc(100% - 10px) 25px/2px calc(100% - 30px),
  /*for the arrows*/
  linear-gradient(to top left,transparent 50%,#000 0%) 10px 100%/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) 0px 100%/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) calc(50% + 5px) 100%/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(50% - 5px) 100%/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) 100% 100%/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(100% - 10px) 100%/10px 10px;
  background-repeat:no-repeat;
}
.arrows:before {
  content:"";
  position:absolute;
  top:20px;
  left:10px;
  right:10px;
  height:8px;
  border:2px solid;
  border-bottom:none;
  border-radius:10px 10px 0 0;
  box-sizing:border-box;
}

<div class="arrows"></div>

How does each arrow work?

For each element we have the line and the extremity:

For the line, we simply need a linear-gradient with a solid color then we adjust the backround-size to control the line:

So if I consider this linear gradient:

body {
  height: 200px;
  border: 1px solid;
  margin:0;
  background: linear-gradient(#000,#000) 10px 25px/2px calc(100% - 30px) no-repeat;
}

We can read it as follow : Draw a line from 10px,25px with a thickness of 2px and a length of 100% minus 30px. 100% will refer to the height of the container.

For the extremity we will need two gradients, each one will create a rectangle triangle. To do this I simply need to specify a diagonal direction to my gradient (for example: to top right):

So if I consider this linear gradient:

body {
  height: 200px;
  border: 1px solid;
  margin:0;
  background: linear-gradient(to top right, #000 50%, transparent 0%) 30px 30px/10px 10px no-repeat;
}

We can read it as follow: start my gradient from 30px,30px with a size of 10px * 10px and fill 50% of it with black following the top right direction. So we will end up with a rectangle triangle having left and bottom side equal to 10px.

We do the same to create the other extremity and we simply make them close to each other to create the final visual:

body {
  height: 200px;
  border: 1px solid;
  margin:0;
  background: 
   linear-gradient(to top right, #000 50%, transparent 0%) 30px 30px/10px 10px no-repeat,
   linear-gradient(to top left,  #000 50%, transparent 0%) 20px 30px/10px 10px no-repeat;
}

Now all you have to do is to combine all these linear gradient and adjust size/position to obtain your layout.

You can easily scale for more arrows if needed as you simply need to append more gradient:

.arrows {
  width:300px;
  height:100px;
  position:relative;
  background:
  /* For the lines*/
  linear-gradient(#000,#000) 10px 25px/2px calc(100% - 50px),
  linear-gradient(#000,#000) 19% 20px/2px calc(100% - 30px),
  linear-gradient(#000,#000) 50% 0/2px calc(100% - 2px),
  linear-gradient(#000,#000) 70% 20px/2px calc(100% - 80px),
  linear-gradient(#000,#000) calc(100% - 10px) 25px/2px calc(100% - 30px),
  linear-gradient(#000,#000) calc(50% + 20px) 60px/ 40px 2px,
  /*for the arrows*/
  linear-gradient(to top left,transparent 50%,#000 0%) 10px calc(100% - 20px)/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) 0px calc(100% - 20px)/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) 20% calc(100% - 8px)/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(20% - 10px) calc(100% - 8px)/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) calc(50% + 5px) 100%/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(50% - 5px) 100%/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) 72% calc(100% - 58px)/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(72% - 10px) calc(100% - 58px)/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) 100% 100%/10px 10px,
  linear-gradient(to top right,transparent 50%,#000 0%) calc(100% - 10px) 100%/10px 10px,
  
  linear-gradient(to top left,transparent 50%,#000 0%) calc(50% + 42px) 62px/10px 10px,
  linear-gradient(to bottom left,transparent 50%,#000 0%) calc(50% + 42px) 52px/10px 10px;
 background-repeat:no-repeat;
}
.arrows:before {
  content:"";
  position:absolute;
  top:20px;
  left:10px;
  right:10px;
  height:8px;
  border:2px solid;
  border-bottom:none;
  border-radius:10px 10px 0 0;
  box-sizing:border-box;
}

<div class="arrows"></div>

回答3:

An arrow in itself is created from an equilateral block of 0 height and width (with only the borders making up the visible element). And then you only show the left border to have a right arrow, the right border for the left arrow and so on and so forth.

https://css-tricks.com/snippets/css/css-triangle/

As far as adding the lines it's a matter of 0 height block elements and the required width for size of horizontal lines and 0 width and the required height for vertical lines.

I went ahead and created the following CSS

    <html>
        <head>
            <title>CSS Arrows</title>
            <style type="text/css">
                .arrow {
                    margin: 5px;
                }

                .arrow_sm {
                    border: 5px solid transparent;
                }

                .arrow_sm p {
                    font-size: 10px;
                    margin-top: -6px;
                }

                .arrow_md {
                    border: 10px solid transparent;
                }

                .arrow_md p {
                    font-size: 20px;
                    margin-top: -12px;
                }

                .arrow_lg {
                    border: 15px solid transparent;
                }

                .arrow_lg p {
                    font-size: 30px;
                    margin-top: -18px;
                }

                .arrow_right {
                    height: 0;
                    border-left-color: blue; 
                }

                .arrow_right {
                    padding-left: 2px;
                }

                .arrow_down {
                    width: 0;
                    border-top-color: red; 
                }

                .arrow_down p {
                    padding-top: 2px;
                    padding-bottom: 2px;
                    transform: rotate(90deg);
                    transform-origin: middle top 0;
                }

                .arrow_left {
                    height: 0;
                    text-align: right;
                    border-right-color: green; 
                }

                .arrow_left p {
                    text-align: right;
                    padding-right: 2px;
                }

                .arrow_up {
                    width: 0;
                    border-bottom-color: black; 
                }

                .arrow_up p {
                    margin: 0 0 -.4em -.2em;
                    transform: rotate(-90deg);
                    transform-origin: middle bottom 0;
                }

                .vertical_line {
                    width: 2px;
                }

                .horizontal_line {
                    height: 2px;
                }

                .line_v_sm {
                    height: 30px;
                    border-left: 2px solid green;
                }

                .line_v_md {
                    height: 45px;
                    border-left: 2px solid red;
                }

                .line_v_lg {
                    height: 60px;
                    border-left: 2px solid black;
                }

                .line_h_sm {
                    width: 30px;
                    border-top: 2px solid green;
                }

                .line_h_md {
                    width: 45px;
                    border-top: 2px solid red;
                }

                .line_h_lg {
                    width: 60px;
                    border-top: 2px solid black;
                }

                .inline {
                    display: inline-block;
                }

                .vertical_stem_sm {
                    margin-top: -.5em;
                    margin-left: .6em;
                    margin-bottom: -.5em;
                }

                .vertical_stem_md {
                    margin-top: -.8em;
                    margin-left: .9em;
                    margin-bottom: -.8em;
                }

                .vertical_stem_lg {
                    margin-top: -1.1em;
                    margin-left: 1.2em;
                    margin-bottom: -1.1em;
                }

                .horizontal_stem_sm {
                    margin-left: -.6em;
                    margin-right: -.6em;
                }

                .horizontal_stem_md {
                    margin-top: -7px;
                    margin-left: -.6em;
                    margin-right: -.6em;
                }

                .horizontal_stem_lg {
                    margin-top: -12px;
                    margin-left: -.6em;
                    margin-right: -.6em;
                }
            </style>
        </head>
        <body>
            <!-- arrow arrow_size arrow_direction //-->
            <div class="arrow arrow_sm arrow_right"><p>Right</p></div>
            <div class="arrow arrow_md arrow_right"><p>Right</p></div>
            <div class="arrow arrow_lg arrow_right"><p>Right</p></div>

            <div class="arrow arrow_sm arrow_down"><p>Down</p></div>
            <div class="arrow arrow_md arrow_down"><p>Down</p></div>
            <div class="arrow arrow_lg arrow_down"><p>Down</p></div>

            <div class="arrow arrow_sm arrow_left"><p>Left</p></div>
            <div class="arrow arrow_md arrow_left"><p>Left</p></div>
            <div class="arrow arrow_lg arrow_left"><p>Left</p></div>

            <div class="arrow arrow_sm arrow_up"><p>Up</p></div>
            <div class="arrow arrow_md arrow_up"><p>Up</p></div>
            <div class="arrow arrow_lg arrow_up"><p>Up</p></div>


            <div class="arrow arrow_sm arrow_right"></div>
            <div class="arrow arrow_md arrow_right"></div>
            <div class="arrow arrow_lg arrow_right"></div>

            <div class="arrow arrow_sm arrow_down"></div>
            <div class="arrow arrow_md arrow_down"></div>
            <div class="arrow arrow_lg arrow_down"></div>

            <div class="arrow arrow_sm arrow_left"></div>
            <div class="arrow arrow_md arrow_left"></div>
            <div class="arrow arrow_lg arrow_left"></div>

            <div class="arrow arrow_sm arrow_up"></div>
            <div class="arrow arrow_md arrow_up"></div>
            <div class="arrow arrow_lg arrow_up"></div>

            <div class="vertical_line line_v_sm"></div>
            <div class="vertical_line line_v_md"></div>
            <div class="vertical_line line_v_lg"></div>

            <div class="horizontal_line line_h_sm"></div>
            <div class="horizontal_line line_h_md"></div>
            <div class="horizontal_line line_h_lg"></div>

            <!-- Small arrow and stem for small arrow //-->
            <div style="margin-left: 70px;">
                <div class="arrow arrow_sm arrow_up"><p>Up</p></div>
                <div class="vertical_line line_v_lg vertical_stem_sm"></div>
            </div>

            <div class="arrow arrow_sm arrow_left inline"><p>Left</p></div>
            <div class="horizontal_line line_h_lg inline horizontal_stem_sm"></div>

            <div class="horizontal_line line_h_lg inline horizontal_stem_sm"></div>
            <div class="arrow arrow_sm arrow_right inline"><p>Right</p></div>
            <div style="margin-left: 70px;">
                <div class="vertical_line line_v_lg vertical_stem_sm"></div>
                <div class="arrow arrow_sm arrow_down"><p>Down</p></div>
            </div>

            <!-- Medium arrow and stem for medium arrow //-->
            <div style="margin-left: 90px;">
                <div class="arrow arrow_md arrow_up"><p>Up</p></div>
                <div class="vertical_line line_v_lg vertical_stem_md"></div>
            </div>

            <div class="arrow arrow_md arrow_left inline"><p>Left</p></div>
            <div class="horizontal_line line_h_lg inline horizontal_stem_md"></div>

            <div class="horizontal_line line_h_lg inline horizontal_stem_md"></div>
            <div class="arrow arrow_md arrow_right inline"><p>Right</p></div>
            <div style="margin-left: 90px;">
                <div class="vertical_line line_v_lg vertical_stem_md"></div>
                <div class="arrow arrow_md arrow_down"><p>Down</p></div>
            </div>

            <!-- Large arrow and stem for large arrow //-->
            <div style="margin-left: 120px;">
                <div class="arrow arrow_lg arrow_up"><p>Up</p></div>
                <div class="vertical_line line_v_lg vertical_stem_lg"></div>
            </div>

            <div class="arrow arrow_lg arrow_left inline"><p>Left</p></div>
            <div class="horizontal_line line_h_lg inline horizontal_stem_lg"></div>

            <div class="horizontal_line line_h_lg inline horizontal_stem_lg"></div>
            <div class="arrow arrow_lg arrow_right inline"><p>Right</p></div>
            <div style="margin-left: 120px;">
                <div class="vertical_line line_v_lg vertical_stem_lg"></div>
                <div class="arrow arrow_lg arrow_down"><p>Down</p></div>
            </div>
        </body>
    </html>

https://jsfiddle.net/2ykpwwgt/1/

For some reason in JSFiddle it doesn't parse like it does in my browser.

Well, you got an idea and something to play with with one method

来源：https://stackoverflow.com/questions/48604103/how-to-code-an-arrow-using-css

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