形状有倾斜的一面(响应)

Question

我试图创建一个如下图所示的形状,仅在一侧(例如,底侧)具有倾斜边缘,而其他边缘保持笔直.

我尝试使用border方法(代码如下),但我的形状的尺寸是动态的,因此我不能使用这种方法.

.shape {
    position: relative;
    height: 100px;
    width: 200px;
    background: tomato;
}
.shape:after {
    position: absolute;
    content: '';
    height: 0px;
    width: 0px;
    left: 0px;
    bottom: -100px;
    border-width: 50px 100px;
    border-style: solid;
    border-color: tomato tomato transparent transparent;
}

<div class="shape">
    Some content
</div>

---

我也尝试使用渐变作为背景(如下面的代码所示),但随着尺寸的变化,它会变得混乱.你可以通过悬停在下面代码片段中的形状来看到我的意思.

.gradient {
  display: inline-block;
  vertical-align: top;
  height: 200px;
  width: 100px;
  margin: 10px;
  color: beige;
  transition: all 1s;
  padding: 10px;
  background: linear-gradient(45deg, transparent 45%, tomato 45%) no-repeat;
}
.gradient:hover {
  width: 200px;
}

<div class="gradient"></div>

如何创建具有倾斜侧面的形状并且还能够支持动态尺寸？

Answer 1

有许多方法可以仅在一侧创建具有倾斜边缘的形状.

以下方法不支持动态大小,如问题中已提到的:

• 具有像素值的边框三角形方法border-width.
• 具有角度语法的线性渐变(如45deg,30deg等).

可以支持动态大小的方法如下所述.

方法1 - SVG

(浏览器兼容性)

SVG可用于通过使用polygons或paths 来生成形状.下面的代码片段使用了polygon.所需的任何文本内容都可以定位在形状的顶部.

$(document).ready(function() {
  $('#increasew-vector').on('click', function() {
    $('.vector').css({
      'width': '150px',
      'height': '100px'
    });
  });
  $('#increaseh-vector').on('click', function() {
    $('.vector').css({
      'width': '100px',
      'height': '150px'
    });
  });
  $('#increaseb-vector').on('click', function() {
    $('.vector').css({
      'width': '150px',
      'height': '150px'
    });
  });
})

div {
  float: left;
  height: 100px;
  width: 100px;
  margin: 20px;
  color: beige;
  transition: all 1s;
}
.vector {
  position: relative;
}
svg {
  position: absolute;
  margin: 10px;
  top: 0px;
  left: 0px;
  height: 100%;
  width: 100%;
  z-index: 0;
}
polygon {
  fill: tomato;
}
.vector > span {
  position: absolute;
  display: block;
  padding: 10px;  
  z-index: 1;
}
.vector.top > span{
  height: 50%;
  width: 100%;
  top: calc(40% + 5px); /* size of the angled area + buffer */
  left: 5px;  
}
.vector.bottom > span{
  height: 50%;
  width: 100%;
  top: 5px;
  left: 5px;  
}
.vector.left > span{
  width: 50%;
  height: 100%;
  left: 50%; /* size of the angled area */
  top: 5px;  
}
.vector.right > span{
  width: 50%;
  height: 100%;
  left: 5px;
  top: 5px;  
}



/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}

polygon:hover, span:hover + svg > polygon{
  fill: steelblue;
}

.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  width: 150px;
}

button {
  width: 150px;
  margin-bottom: 10px;
}

.vector.left{
  clear: both;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="vector bottom">
  <span>Some content</span>
  <svg viewBox="0 0 40 100" preserveAspectRatio="none">
    <polygon points="0,0 40,0 40,100 0,60" />
  </svg>
</div>
<div class="vector top">
  <span>Some content</span>
  <svg viewBox="0 0 40 100" preserveAspectRatio="none">
    <polygon points="0,40 40,0 40,100 0,100" />
  </svg>
</div>
<div class="vector left">
  <span>Some content</span>
  <svg viewBox="0 0 40 100" preserveAspectRatio="none">
    <polygon points="0,0 40,0 40,100 20,100" />
  </svg>
</div>
<div class="vector right">
  <span>Some content</span>
  <svg viewBox="0 0 40 100" preserveAspectRatio="none">
    <polygon points="0,0 20,0 40,100 0,100" />
  </svg>
</div>

<div class='btn-container'>
  <button id="increasew-vector">Increase Width</button>
  <button id="increaseh-vector">Increase Height</button>
  <button id="increaseb-vector">Increase Both</button>
</div>

优点

• SVG旨在生成可扩展的图形,并且可以很好地适应所有尺寸变化.
• 可以用最小的编码开销实现边界和悬停效果.
• 还可以向形状提供图像或梯度背景.

缺点

• 浏览器支持可能是唯一的缺点,因为IE8-不支持SVG,但可以通过使用Raphael和VML等库来减轻这种影响.此外,浏览器支持绝不比其他选项更糟糕.

方法2 - 渐变背景

(浏览器兼容性)

线性渐变仍可用于生成形状,但不能用于问题中提到的角度.我们必须使用to [side] [side]语法(感谢vals)而不是指定角度.指定边时,会根据容器的尺寸自动调整渐变角度.

$(document).ready(function() {
  $('#increasew-gradient').on('click', function() {
    $('.gradient').css({
      'height': '100px',
      'width': '150px'
    });
  });
  $('#increaseh-gradient').on('click', function() {
    $('.gradient').css({
      'height': '150px',
      'width': '100px'
    });
  });
  $('#increaseb-gradient').on('click', function() {
    $('.gradient').css({
      'height': '150px',
      'width': '150px'
    });
  });
})

div {
  float: left;
  height: 100px;
  width: 100px;
  margin: 10px 20px;
  color: beige;
  transition: all 1s;
}
.gradient{
  position: relative;
}
.gradient.bottom {
  background: linear-gradient(to top right, transparent 50%, tomato 50%) no-repeat, linear-gradient(to top right, transparent 0.1%, tomato 0.1%) no-repeat;
  background-size: 100% 40%, 100% 60%;
  background-position: 0% 100%, 0% 0%;
}
.gradient.top {
  background: linear-gradient(to bottom right, transparent 50%, tomato 50%) no-repeat, linear-gradient(to bottom right, transparent 0.1%, tomato 0.1%) no-repeat;
  background-size: 100% 40%, 100% 60%;
  background-position: 0% 0%, 0% 100%;
}
.gradient.left {
  background: linear-gradient(to top right, transparent 50%, tomato 50%) no-repeat, linear-gradient(to top right, transparent 0.1%, tomato 0.1%) no-repeat;
  background-size: 40% 100%, 60% 100%;
  background-position: 0% 0%, 100% 0%;
}
.gradient.right {
  background: linear-gradient(to top left, transparent 50%, tomato 50%) no-repeat, linear-gradient(to top left, transparent 0.1%, tomato 0.1%) no-repeat;
  background-size: 40% 100%, 60% 100%;
  background-position: 100% 0%, 0% 0%;
}
.gradient span{
  position: absolute;
}
.gradient.top span{
  top: calc(40% + 5px); /* background size + buffer */ 
  left: 5px;
  height: 50%;
}
.gradient.bottom span{
  top: 5px;
  left: 5px;
  height: 50%;
}
.gradient.left span{
  left: 40%; /* background size */
  top: 5px;
  width: 50%;
}
.gradient.right span{
  left: 5px;
  top: 5px;
  width: 50%;
}

/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}

.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  width: 150px;
}
button {
  width: 150px;
  margin-bottom: 10px;
}
.gradient.left{
  clear:both;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="gradient bottom"><span>Some content</span>
</div>
<div class="gradient top"><span>Some content</span>
</div>
<div class="gradient left"><span>Some content</span>
</div>
<div class="gradient right"><span>Some content</span>
</div>

<div class='btn-container'>
  <button id="increasew-gradient">Increase Width</button>
  <button id="increaseh-gradient">Increase Height</button>
  <button id="increaseb-gradient">Increase Both</button>
</div>

优点

• 即使容器的尺寸是动态的,也可以实现和保持形状.
• Hover effect can be added by changing the gradient color.

Cons

• Hover effect will be triggered even when cursor is outside the shape but within the container.
• Adding borders would require tricky gradient manipulations.
• Gradients are known for producing jagged corners when the width (or height) is very big.
• Image backgrounds cannot be used on the shape.

Method 3 - Skew Transforms

(Browser Compatibility)

In this method, a pseudo-element is added, skewed and positioned in such a way that it looks like one of the edges is slanted/angled.If the top or bottom edge is slanted, the skew should be along Y axis, else the rotation should be along X axis. The transform-origin should have the side opposite to the slanted side.

$(document).ready(function() {
  $('#increasew-skew').on('click', function() {
    $('.skew').css({
      'height': '100px',
      'width': '150px'
    });
  });
  $('#increaseh-skew').on('click', function() {
    $('.skew').css({
      'height': '150px',
      'width': '100px'
    });
  });
  $('#increaseb-skew').on('click', function() {
    $('.skew').css({
      'height': '150px',
      'width': '150px'
    });
  });
})

div {
  float: left;
  height: 100px;
  width: 100px;
  margin: 50px;
  color: beige;
  transition: all 1s;
}
.skew {
  padding: 10px;
  position: relative;
  background: tomato;
}
.skew:after {
  position: absolute;
  content: '';
  background: inherit;
  z-index: -1;
}
.skew.bottom:after,
.skew.top:after {
  width: 100%;
  height: 60%;
}
.skew.left:after,
.skew.right:after {
  height: 100%;
  width: 60%;
}
.skew.bottom:after {
  bottom: 0px;
  left: 0px;
  transform-origin: top left;
  transform: skewY(22deg);
}
.skew.top:after {
  top: 0px;
  left: 0px;
  transform-origin: top left;
  transform: skewY(-22deg);
}
.skew.left:after {
  top: 0px;
  left: 0px;
  transform-origin: bottom left;
  transform: skewX(22deg);
}
.skew.right:after {
  top: 0px;
  right: 0px;
  transform-origin: bottom right;
  transform: skewX(-22deg);
}
.skew:hover {
  background: steelblue;
}
/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}
.skew.bottom {
  margin-top: 10px;
}
.skew.left {
  clear: both;
}
.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  width: 150px;
}
button {
  width: 150px;
  margin-bottom: 10px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="skew bottom">Some content</div>
<div class="skew top">Some content</div>
<div class="skew left">Some content</div>
<div class="skew right">Some content</div>

<div class='btn-container'>
  <button id="increasew-skew">Increase Width</button>
  <button id="increaseh-skew">Increase Height</button>
  <button id="increaseb-skew">Increase Both</button>
</div>

Pros

• Shape can be achieved even with borders.
• Hover effect will be restricted to within the shape.

Cons

• Dimensions need to increase proportionally for the shape to be maintained because when an element is skewed, its offset in Y-axis increases as width increases and vice-versa (try increasing the width to 200px in the snippet). You can find more information about this here.

Method 4 - Perspective Transforms

(Browser Compatibility)

In this method, the main container is rotated along the X or Y axis with a bit of perspective. Setting the appropriate value to transform-origin would produce a slanted edge on only one side.

If the top or bottom side is slanted, the rotation should be along Y axis, else the rotation should be along X axis. The transform-origin should have the side opposite to the slanted side.

$(document).ready(function() {
  $('#increasew-rotate').on('click', function() {
    $('.rotate').css({
      'height': '100px',
      'width': '150px'
    });
  });
  $('#increaseh-rotate').on('click', function() {
    $('.rotate').css({
      'height': '150px',
      'width': '100px'
    });
  });
  $('#increaseb-rotate').on('click', function() {
    $('.rotate').css({
      'height': '150px',
      'width': '150px'
    });
  });
})

div {
  float: left;
  height: 100px;
  width: 100px;
  margin: 50px;
  color: beige;
  transition: all 1s;
}
.rotate {
  position: relative;
  width: 100px;
  background: tomato;
}
.rotate.bottom {
  transform-origin: top;
  transform: perspective(10px) rotateY(-2deg);
}
.rotate.top {
  transform-origin: bottom;
  transform: perspective(10px) rotateY(-2deg);
}
.rotate.left {
  transform-origin: right;
  transform: perspective(10px) rotateX(-2deg);
}
.rotate.right {
  transform-origin: left;
  transform: perspective(10px) rotateX(-2deg);
}
.rotate span {
  position: absolute;
  display: block;
  top: 0px;
  right: 0px;
  width: 50%;
  height: 100%;
}
.rotate.bottom span {
  padding: 10px;
  transform-origin: top;
  transform: perspective(10px) rotateY(2deg);
}
.rotate.top span {
  padding: 20px;
  transform-origin: bottom;
  transform: perspective(20px) rotateY(2deg);
}
.rotate.left span {
  padding: 10px;
  transform-origin: right;
  transform: perspective(10px) rotateX(2deg);
}
.rotate.right span {
  padding: 0px 30px;
  transform-origin: left;
  transform: perspective(10px) rotateX(2deg);
}
.rotate:hover {
  background: steelblue;
}

/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}
.rotate.left{
  clear:both;
}
.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  width: 150px;
}
button {
  width: 150px;
  margin-bottom: 10px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="rotate bottom"><span>Some content</span>
</div>
<div class="rotate top"><span>Some content</span>
</div>
<div class="rotate left"><span>Some content</span>
</div>
<div class="rotate right"><span>Some content</span>
</div>

<div class='btn-container'>
  <button id="increasew-rotate">Increase Width</button>
  <button id="increaseh-rotate">Increase Height</button>
  <button id="increaseb-rotate">Increase Both</button>
</div>

Pros

• Shape can be achieved with borders.
• Dimensions need not increase proportionally for the shape to be maintained.

Cons

• Content will also be rotated and hence they have to be counter rotated to look normal.
• Positioning text will be tedious if the dimensions are not static.

Method 5 - CSS Clip Path

(Browser Compatibility)

In this method, the main container is clipped into the required shape using a polygon. The polygon's points should be modified depending on the side where the slanted edge is required.

$(document).ready(function() {
  $('#increasew-clip').on('click', function() {
    $('.clip-path').css({
      'height': '100px',
      'width': '150px'
    });
  });
  $('#increaseh-clip').on('click', function() {
    $('.clip-path').css({
      'height': '150px',
      'width': '100px'
    });
  });
  $('#increaseb-clip').on('click', function() {
    $('.clip-path').css({
      'height': '150px',
      'width': '150px'
    });
  });
})

.clip-path {
  position: relative;
  float: left;
  margin: 20px;
  height: 100px;
  width: 100px;
  background: tomato;
  padding: 4px;
  transition: all 1s;
}
.clip-path.bottom {
  -webkit-clip-path: polygon(0% 0%, 100% 0%, 100% 100%, 0% 60%);
}
.clip-path.top {
  -webkit-clip-path: polygon(0% 40%, 100% 0%, 100% 100%, 0% 100%);
}
.clip-path.left {
  -webkit-clip-path: polygon(0% 0%, 100% 0%, 100% 100%, 40% 100%);
}
.clip-path.right {
  -webkit-clip-path: polygon(0% 0%, 60% 0%, 100% 100%, 0% 100%);
}
.clip-path .content {
  position: absolute;
  content: '';
  height: calc(100% - 10px);
  width: calc(100% - 8px);
  background: bisque;
}
.clip-path.bottom .content {
  -webkit-clip-path: polygon(0% 0%, 100% 0%, 100% 100%, 0% 60%);
}
.clip-path.top .content {
  -webkit-clip-path: polygon(0% 40%, 100% 0%, 100% 100%, 0% 100%);
}
.clip-path .content.img {
  top: 6px;
  background: url(http://lorempixel.com/250/250);
  background-size: 100% 100%;
}
/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}
.clip-path.left {
  clear: both;
}
.clip-path:hover {
  background: gold;
}
.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  margin: 20px;
  width: 150px;
}
button {
  width: 150px;
  margin-bottom: 10px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="clip-path bottom">
  <div class="content">abcd</div>
</div>
<div class="clip-path top">
  <div class="content img"></div>
</div>
<div class="clip-path left"></div>
<div class="clip-path right"></div>

<div class='btn-container'>
  <button id="increasew-clip">Increase Width</button>
  <button id="increaseh-clip">Increase Height</button>
  <button id="increaseb-clip">Increase Both</button>
</div>

Pros

• Shape can be maintained even when the container is being resized dynamically.
• Hover effect will be perfectly restricted within the borders of the shape.
• Image can also be used as background for the shape.

Cons

• Browser support is very poor at present.
• Borders can be added by placing an absolutely positioned element on top of the shape and giving it the necessary clip but beyond a point it doesn't fit well when re-sizing dynamically.

Method 6 - Canvas

(Browser Compatibility)

Canvas can also be used to produce the shape by drawing paths. The below snippet has a demo. Any text content required can be positioned on top of the shape.

window.onload = function() {
  var canvasEls = document.getElementsByTagName('canvas');
  for (var i = 0; i < canvasEls.length; i++) {
    paint(canvasEls[i]);
  }

  function paint(canvas) {
    var ctx = canvas.getContext('2d');
    ctx.beginPath();
    if (canvas.className == 'bottom') {
      ctx.moveTo(0, 0);
      ctx.lineTo(250, 0);
      ctx.lineTo(250, 100);
      ctx.lineTo(0, 60);
    } else if (canvas.className == 'top') {
      ctx.moveTo(0, 40);
      ctx.lineTo(250, 0);
      ctx.lineTo(250, 100);
      ctx.lineTo(0, 100);
    } else if (canvas.className == 'left') {
      ctx.moveTo(0, 0);
      ctx.lineTo(250, 0);
      ctx.lineTo(250, 100);
      ctx.lineTo(60, 100);
    } else if (canvas.className == 'right') {
      ctx.moveTo(0, 0);
      ctx.lineTo(190, 0);
      ctx.lineTo(250, 100);
      ctx.lineTo(0, 100);
    }
    ctx.closePath();
    ctx.lineCap = 'round';
    ctx.fillStyle = 'tomato';
    ctx.fill();
  }
  $('#increasew-canvas').on('click', function() {
    $('.container').css({
      'width': '150px',
      'height': '100px'
    });
  });
  $('#increaseh-canvas').on('click', function() {
    $('.container').css({
      'width': '100px',
      'height': '150px'
    });
  });
  $('#increaseb-canvas').on('click', function() {
    $('.container').css({
      'width': '150px',
      'height': '150px'
    });
  });
};

.container {
  float: left;
  position: relative;
  height: 100px;
  width: 100px;
  margin: 20px;
  color: beige;
  transition: all 1s;
}
canvas {
  height: 100%;
  width: 100%;
}
.container > span {
  position: absolute;
  top: 5px;
  left: 5px;
  padding: 5px;
}
.top + span {
  top: 40%; /* size of the angled area */
}
.left + span {
  left: 40%; /* size of the angled area */
}

/* Just for demo */

body {
  background: radial-gradient(circle at 50% 50%, aliceblue, steelblue);
}
.btn-container {
  position: absolute;
  top: 0px;
  right: 0px;
  width: 150px;
}
button {
  width: 150px;
  margin-bottom: 10px;
}
div:nth-of-type(3) {
  clear: both;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<div class="container">
  <canvas height="100px" width="250px" class="bottom"></canvas> <span>Some content</span>

</div>
<div class="container">
  <canvas height="100px" width="250px" class="top"></canvas> <span>Some content</span>

</div>
<div class="container">
  <canvas height="100px" width="250px" class="left"></canvas> <span>Some content</span>

</div>
<div class="container">
  <canvas height="100px" width="250px" class="right"></canvas> <span>Some content</span>

</div>
<div class='btn-container'>
  <button id="increasew-canvas">Increase Width</button>
  <button id="increaseh-canvas">Increase Height</button>
  <button id="increaseb-canvas">Increase Both</button>
</div>

Pros

• Shape can be achieved and maintained even if the dimensions of the container are dynamic. Borders can also be added.
• Hover effect can be restricted to within the shape's boundaries by using pointInpath method.
• Image or gradient background can also be provided to the shape.
• Better choice if real-time animation effects are needed as it doesn't require DOM manipulation.

Cons

• Canvas is raster based and hence the angled edges will become pixelated or blurred when scaled beyond a point ^*.

^{*- Avoiding pixelation would need repaints of the shape whenever viewport is resized. There is an example of it here but that is an overhead.}

Answer 2

我尝试使用border方法,但我的形状的尺寸是动态的,因此我不能使用这种方法.

方法7 - 视口单元 ^{(Border Redux)}

(浏览器兼容性)

Viewport Units是CSS3的一项伟大创新.虽然您通常可以使用百分比值来动态化您的属性,但您不能为border-widths(也不是font-sizes)执行此操作.

相反,使用视口单元,您可以动态设置边框宽度以及对象的大小,与视口尺寸进行比较.

_{注意:百分比值是指父对象,而不是视口(窗口的可见区域).}

要测试该方法,请启动以下片段"整页"并水平和垂直调整其大小.

.shape {
    position: relative;
    height: 20vh;
    width: 40vw;
    background: tomato;
}
.shape:after {
    position: absolute;
    content: '';
    left: 0px;
    right: 0px;
    top: 20vh;
    border-width: 10vh 20vw;
    border-style: solid;
    border-color: tomato tomato rgba(0,0,0,0) rgba(0,0,0,0);
}

<div class="shape">Some content</div>

优点 - (1)一切都是动态的,浏览器覆盖范围很广.

缺点 - (1)你应该注意你的操作系统如何处理滚动使用overflow: auto;.