CSS繪製簡單圖形

究竟該用字體圖標、圖片圖標、還是CSS畫一個圖標？我也不知道。各有千秋吧。本文將介紹如何用css繪製簡單的圖形，所有測試在chrome58.0完成，如果你不能得到正確結果請到caniuse查一查看看是不是需要什麼前綴。

一、基礎

<!DOCTYPE html>
<html>
<head>
    <title>basic shapes</title>
    <style type="text/css">
        div{
            box-sizing: border-box;
        }
        .div1{
            width: 100px;
            height: 100px;
            border-top: 50px solid red;
            border-right: 50px solid blue;
            border-bottom: 50px solid yellow;
            border-left: 50px solid green;
        }

        .div2{
            width: 100px;
            height: 100px;
            border-right: 50px solid blue;
            border-bottom: 100px solid yellow;
            border-left: 50px solid green;
        }
        .div3{
            width: 100px;
            height: 100px;
            border-right: 25px solid blue;
            border-bottom: 100px solid yellow;
            border-left: 25px solid green;
        }
    </style>
</head>
<body>
    <div class="div1">div1</div>
    <span>border的神奇之處</span>
    <hr>
    <div class="div2">div2</div>
    <span>黃色三角形，底邊100px高100px</span>
    <hr>
    <div class="div3">div3</div>
    <span>黃色的等腰梯形，上底50,下底100,高100</span>
</body>
</html>

　　上面代碼的效果是這樣的

　　border是如何工作的，你可以從上面的結果自行體會。

二、特殊三角形

<!DOCTYPE html>
<html>
<head>
    <title>三角形</title>
    <style type="text/css">
        div{
            box-sizing: border-box;
            margin:20px;
        }
        .container::after{
            content: "";
            display: block;
            clear: both;
        }
        .div1{
            width: 100px;
            height: 0;
            border-bottom: 100px solid red;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            float: left;
        }
        .div2{
            width: 0;
            height: 100px;
            border-bottom: 50px solid transparent;
            border-left: 100px solid blue;
            border-top: 50px solid transparent;
            float: left;
        }
        .div3{
            width: 100px;
            height: 0;
            border-top: 100px solid yellow;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            float: left;
        }
        .div4{
            width: 0;
            height: 100px;
            border-bottom: 50px solid transparent;
            border-right: 100px solid green;
            border-top: 50px solid transparent;
            float: left;
        }
        .div5{
            width: 100px;
            height: 0;
            border-bottom: 86.6px solid red;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            float: left;
        }
        .div6{
            width: 100px;
            height: 0;
            border-bottom: 100px solid blue;
            /*border-left: 50px solid transparent;*/
            border-right: 100px solid transparent;
            float: left;
        }
        .div7{
            width: 100px;
            height: 0;
            border-bottom: 100px solid blue;
            /*border-left: 50px solid transparent;*/
            border-right: 100px solid transparent;
            float: left;
            transform: rotate(135deg);
            transform-origin: 50% 50%;
        }
    </style>
</head>
<body>
    <div class="container">
        <h4>等腰三角形</h4>
        <div class="div1"></div>
        <div class="div2"></div>
        <div class="div3"></div>
        <div class="div4"></div>
    </div>
    <div class="container">
        <h4>其他特殊三角形</h4>
        <div class="div5">等邊</div>
        <div class="div6">直角</div>
        <div class="div7">直角</div>
    </div>
</body>
</html>

　　等腰三角形我做了4個方向的，當然你也可以用旋轉來做，就像div7那樣。製作三角形比較簡單，只要對我前面將的基礎加以改造就可以了。

三、特殊四邊形

<!DOCTYPE html>
<html>
<head>
    <title>四邊形</title>
    <style type="text/css">
        div{
            box-sizing: border-box;
            margin:20px;
        }
        .container::after{
            content: "";
            display: block;
            clear: both;
        }
        .div1{
            background: transparent;
            width: 0;
            height: 100px;
            border-bottom: 50px solid transparent;
            border-right: 100px solid green;
            border-top: 50px solid transparent;
            float: left;
            position: relative;
            box-sizing: border-box;

        }
        .div1::after{
            content: "";
            position: absolute;
            top: -50px;
            left: 100px;
            background: transparent;
            width: 0;
            height: 100px;
            border-bottom: 50px solid transparent;
            border-left: 100px solid green;
            border-top: 50px solid transparent;
            float: left;
            position: relative;
            box-sizing: border-box;
        }

        .div2{
            background: transparent;
            width: 80px;
            height: 0;
            border-bottom: 50px solid green;
            border-right: 40px solid transparent;
            border-left: 40px solid transparent;
            float: left;
            position: relative;
            box-sizing: border-box;
            margin-left: 100px;
        }
        .div2::after{
            content: "";
            position: absolute;
            top: 50px;
            left: -40px;
            width: 80px;
            height: 0;
            border-top: 50px solid green;
            border-right: 40px solid transparent;
            border-left: 40px solid transparent;
            box-sizing: border-box;
        }
        .div5{
            width: 100px;
            height: 0;
            border-bottom: 100px solid green;
            border-left: 25px solid transparent;
            border-right: 25px solid transparent;
            float: left;
        }
        .div6{
            width: 100px;
            height: 0;
            border-bottom: 100px solid green;
            border-right: 40px solid transparent;
            float: left;
        }
        .div7{
            width: 100px;
            height: 100px;
            background: green;
            transform: skew(30deg,0);
            float: left;
        }
    </style>
</head>
<body>
    <div class="container">
        <h4>菱形</h4>
        <div class="div1"></div>
        <div class="div2"></div>
    </div>
    <div class="container">
        <h4>梯形和平行四邊形</h4>
        <div class="div5">等腰</div>
        <div class="div6">直角</div>
        <div class="div7">平行四邊形</div>
    </div>
</body>
</html>

四、圓和橢圓

<!DOCTYPE html>
<html>
<head>
    <title>圓和橢圓</title>
    <style type="text/css">
        .div1{
            width: 50px;
            height: 50px;
            border-radius: 25px;
            box-sizing: border-box;
            background: red;
            float: left;
        }
        .div2 {
            width: 100px; 
            height: 80px; 
            background: green; 
            border-radius: 50px / 40px; 
            float: left;
        }
    </style>
</head>
<body>
    <div class="div1"></div>
    <div class="div2"></div>
</body>
</html>

　　科普一下：http://www.css88.com/book/css/properties/border/border-radius.htm

　　以前都只用一個參參數的，所以寫博客可以幫助查漏補缺。

五、複雜一點的圖形

　　1、正多邊形

<!DOCTYPE html>
<html>
<head>
    <title>正多邊形</title>
    <style type="text/css">
        .five {   
            top: 50px;
            position: relative;  
            width: 54px;     
            border-width: 50px 18px 0;     
            border-style: solid;     
            border-color: red transparent; 
        } 
        .five::before {     
            content: "";     
            position: absolute;     
            height: 0;    
            width: 0;     
            top: -85px;     
            left: -18px;     
            border-width: 0 45px 35px;     
            border-style: solid;     
            border-color: transparent transparent green; 
        }
        .six{
            width: 100px;
            height: 0px;
            border-width:0px 18.59px 60px;
            border-style: solid;
            border-color: transparent transparent red; 
            margin-top: 60px;
            position: relative;
        }
        .six::after{
            content: "";
            width: 100px;
            height: 0px;
            border-width:60px 18.59px 0px;
            border-style: solid;
            border-color: green transparent transparent; 
            position: absolute;
            top: 60px;
            left: -18.59px;
        }
    </style>
</head>
<body>
    <div class="five"></div>
    <div class="six"></div>
</body>
</html>

　　正五邊形是借鑑的大神的（不知道是不是正的，我沒算），思路是做一個梯形，然後拼接一個三角形，正六邊形是我根據他的思路用兩個梯形拼接的，如果我沒有計算錯誤這應該是一個正六邊形（怎麼有點不像呢），計算目的是保證，腰和短底長相等。我刻意用不同顏色表示了拆分情況，便於理解。正八變形怎麼做？只需要拆解成兩個梯形和一個矩形就好做了。正n邊形怎麼做，也是把它看作基本圖形的組合，只不過可能單靠兩個僞元素已經不夠用了。

　　2、大大的愛心送給你

.aixin{
            border-width: 200px 150px 0;
            border-style: solid;;
            border-color: red transparent;
            width: 0px;
            position: relative;
            top: 200px;
            left: 100px;
        }
        .aixin::before{
            content: "";
            width: 180px;
            height: 180px;
            display: block;
            border-radius: 90px;
            background: red;
            position: absolute;
            top: -357px;
            left: -180px;
        }
        .aixin:after{
            content: "";
            width: 180px;
            height: 180px;
            display: block;
            border-radius: 90px;
            background: red;
            position: absolute;
            top: -357px;
            left: 0;
        }

　　數據沒算，調整出來的。人要實心啊，搞個空心太不像話了，你自己去弄吧。兩個圈圈加個三角形就可以了，原來愛這麼簡單。　　　　

　　3、對話框

<!DOCTYPE html>
<html>
<head>
    <title>對話框</title>
    <style type="text/css">
        .div1{
            width: 300px;
            height: 100px;
            border: 1px solid #97FFFF;
            position: relative;
            left: 100px;
            border-radius: 10px;
        }
        .div1::after,.div1::before{
            content: "";
            
            display: block;
            width: 0;
            height: 0;
            border-style: solid;
            border-color:transparent #97FFFF transparent transparent;
            position: absolute;
            top: 30px;
            left: -50px;
        }
        .div1::after{
            border-width: 21px 50px 21px 0;
        }
        .div1::before{
            top: 31px;
            border-width: 20px 50px 20px 0;
            border-color: transparent white transparent transparent;
            z-index: 1000;
            left: -49px;
        }
        
        .div2{
            width: 300px;
            height: 100px;
            border: 1px solid #97FFFF;
            position: relative;
            left: 100px;
            border-radius: 10px;
            margin-top: 20px;
        }
        .div2::after,.div2::before{
            content: "";
            
            display: block;
            width: 0;
            height: 0;
            border-style: solid;
            border-color:transparent transparent transparent #97FFFF;
            position: absolute;
            top: 30px;
            left: 300px;
        }
        .div2::after{
            border-width: 21px 0px 21px 50px;
        }
        .div2::before{
            top: 31px;
            border-width: 20px 0px 20px 50px;
            border-color: transparent transparent transparent white;
            z-index: 1000;
            left: 299px;
        }
        
    </style>
</head>
<body>
    <div class="div1">    
    </div>
    

    <div class="div2"></div>

</body>
</html>

六、小結一下

　　用CSS還是畫出來很多東西的，對於稍微複雜點的圖形用拼接或者裁剪的方法實現，有時可能會需要一些簡單計算。本文所提到的只是九牛一毛，早有一些朋友做出了許多非常炫酷的圖形，你可以去搜搜看。就寫到這裏，留幾個大神的作品，以備不時只需。

參考：

CSS繪製簡單圖形

一、基礎

二、特殊三角形

三、特殊四邊形

四、圓和橢圓

五、複雜一點的圖形

六、小結一下

媒體查詢

CSS基礎佈局--居中對齊，左側定寬右側自適應

AngularJS1.X學習筆記1-整體看看

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