我试图在悬停时用css过渡缩略图,这样在悬停时,背景渐变就会淡入。转换没有工作,但如果我简单地将其更改为rgba()值,它就可以工作。不支持渐变吗?我也尝试使用图像,它也不会过渡图像。

我知道这是可能的,因为在另一篇文章中有人做到了,但我不知道具体是怎么做到的。这里有一些CSS工作:

#container div a {
  -webkit-transition: background 0.2s linear;
  -moz-transition: background 0.2s linear;
  -o-transition: background 0.2s linear;
  transition: background 0.2s linear;
  position: absolute;
  width: 200px;
  height: 150px;
  border: 1px #000 solid;
  margin: 30px;
  z-index: 2
}

#container div a:hover {
  background: -webkit-gradient(radial, 100 75, 100, 100 75, 0, from(rgba(0, 0, 0, .7)), to(rgba(0, 0, 0, .4)))
}

当前回答

2021年:现在可以动画渐变了(Firefox和Safari还不行)

随着Chrome 85, Edge和Opera添加了对@property规则的支持,现在我们可以在CSS中这样做:

@property --myColor1 {
  syntax: '<color>';
  initial-value: magenta;
  inherits: false;
}

@property --myColor2 {
  syntax: '<color>';
  initial-value: green;
  inherits: false;
}

其余都是常规的CSS。 设置变量为初始渐变颜色,并设置这些变量的过渡:

div {
  /* Optional: change initial value of the variables */
  /* --myColor1: #f64; --myColor2: brown; */

  background: linear-gradient(var(--myColor1), var(--myColor2));
  transition: --myColor1 3s, --myColor2 3s;
}

然后,在所需的规则上,为变量设置新的值:

div:hover {  
  --myColor1: #f00;
  --myColor2: yellow;
}

@property——myColor1 { 语法:“< >颜色”; 初值:# 0 f0; 继承:错误; } @property——myColor2 { 语法:“< >颜色”; 初始值:rgb(40,190,145); 继承:错误; } div { 宽度:200 px; 身高:100 px; background: linear-gradient(var(——myColor1), var(——myColor2)); ——myColor1 3s,——myColor2 3s; } div:{徘徊 ——myColor1:红色; ——myColor2: # E1AF2F; } <div>悬停在我上方</div>

在这里查看完整的描述和示例,并参考这里的@property规范。 @property规则是CSS Houdini技术的一部分。要了解更多信息,请参考这里和这里,并观看这个视频。

其他回答

2021年:现在可以动画渐变了(Firefox和Safari还不行)

随着Chrome 85, Edge和Opera添加了对@property规则的支持,现在我们可以在CSS中这样做:

@property --myColor1 {
  syntax: '<color>';
  initial-value: magenta;
  inherits: false;
}

@property --myColor2 {
  syntax: '<color>';
  initial-value: green;
  inherits: false;
}

其余都是常规的CSS。 设置变量为初始渐变颜色,并设置这些变量的过渡:

div {
  /* Optional: change initial value of the variables */
  /* --myColor1: #f64; --myColor2: brown; */

  background: linear-gradient(var(--myColor1), var(--myColor2));
  transition: --myColor1 3s, --myColor2 3s;
}

然后,在所需的规则上,为变量设置新的值:

div:hover {  
  --myColor1: #f00;
  --myColor2: yellow;
}

@property——myColor1 { 语法:“< >颜色”; 初值:# 0 f0; 继承:错误; } @property——myColor2 { 语法:“< >颜色”; 初始值:rgb(40,190,145); 继承:错误; } div { 宽度:200 px; 身高:100 px; background: linear-gradient(var(——myColor1), var(——myColor2)); ——myColor1 3s,——myColor2 3s; } div:{徘徊 ——myColor1:红色; ——myColor2: # E1AF2F; } <div>悬停在我上方</div>

在这里查看完整的描述和示例,并参考这里的@property规范。 @property规则是CSS Houdini技术的一部分。要了解更多信息,请参考这里和这里,并观看这个视频。

在下面的例子中,一个锚标记有一个子标记和一个孙子标记。孙子有远背景梯度。近背景中的子元素是透明的,但是有渐变要过渡。在悬停时,子物体的不透明度在1秒内从0过渡到1。

下面是CSS:

.bkgrndfar {
  position:absolute;
  top:0;
  left:0;
  z-index:-2;
  height:100%;
  width:100%;
  background:linear-gradient(#eee, #aaa);
}

.bkgrndnear {
  position:absolute;
  top:0;
  left:0;
  height:100%;
  width:100%;
  background:radial-gradient(at 50% 50%, blue 1%, aqua 100%);
  opacity:0;
  transition: opacity 1s;
}

a.menulnk {
  position:relative;
  text-decoration:none;
  color:#333;
  padding: 0 20px;
  text-align:center;
  line-height:27px;
  float:left;
}

a.menulnk:hover {
  color:#eee;
  text-decoration:underline;
}

/* This transitions child opacity on parent hover */
a.menulnk:hover .bkgrndnear {
  opacity:1;
}

这是HTML:

<a href="#" class="menulnk">Transgradient
<div class="bkgrndfar">
  <div class="bkgrndnear">
  </div>
</div>
</a>

以上仅在最新版本的Chrome中进行测试。这些是悬停前,悬停中途和完全过渡的悬停图像:

一个更简洁的解决方案是设置背景色并使用蒙版图像。

#container div a {
  background-color: blue;
  transition: background 0.2s linear;
  width: 200px;
  height: 150px;
  mask-image: radial-gradient(circle at 50% 50%, rgba(0, 0, 0, .7), rgba(0, 0, 0, .4));
}

#container div a:hover { 
  background-color: red;
}

发布另一个视图也无妨,因为仍然没有一个官方的方法来做到这一点。写了一个轻量级的jQuery插件,你可以用它来定义背景径向渐变和过渡速度。这个基本的用法会让它淡入,用requestAnimationFrame优化(非常流畅):

$('#element').gradientFade({

    duration: 2000,
    from: '(20,20,20,1)',
    to: '(120,120,120,0)'
});

http://codepen.io/Shikkediel/pen/xbRaZz?editors=001

保持原始背景和所有属性完整。也有高亮跟踪作为设置:

http://codepen.io/Shikkediel/pen/VYRZZY?editors=001

我知道这是一个老问题,但也许有人喜欢我在纯CSS解决方案的方式。从左到右渐变。

.contener{ width:300px; height:200px; background-size:cover; border:solid 2px black; } .ed { width: 0px; height: 200px; background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75)); position: relative; opacity:0; transition:width 20s, opacity 0.6s; } .contener:hover .ed{ width: 300px; background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75)); position: relative; opacity:1; transition:width 0.4s, opacity 1.1s; transition-delay: width 2s; animation-name: gradient-fade; animation-duration: 1.1s; -webkit-animation-name: gradient-fade; /* Chrome, Safari, Opera */ -webkit-animation-duration: 1.1s; /* Chrome, Safari, Opera */ } /* ANIMATION */ @-webkit-keyframes gradient-fade { 0% {background:linear-gradient(to right, rgba(0,0,255,0), rgba(255,0,0,0));} 2% {background:linear-gradient(to right, rgba(0,0,255,0.01875), rgba(255,0,0,0));} 4% {background:linear-gradient(to right, rgba(0,0,255,0.0375), rgba(255,0,0,0.0));} 6% {background:linear-gradient(to right, rgba(0,0,255,0.05625), rgba(255,0,0,0.0));} 8% {background:linear-gradient(to right, rgba(0,0,255,0.075), rgba(255,0,0,0));} 10% {background:linear-gradient(to right, rgba(0,0,255,0.09375), rgba(255,0,0,0));} 12% {background:linear-gradient(to right, rgba(0,0,255,0.1125), rgba(255,0,0,0));} 14% {background:linear-gradient(to right, rgba(0,0,255,0.13125), rgba(255,0,0,0));} 16% {background:linear-gradient(to right, rgba(0,0,255,0.15), rgba(255,0,0,0));} 18% {background:linear-gradient(to right, rgba(0,0,255,0.16875), rgba(255,0,0,0));} 20% {background:linear-gradient(to right, rgba(0,0,255,0.1875), rgba(255,0,0,0));} 22% {background:linear-gradient(to right, rgba(0,0,255,0.20625), rgba(255,0,0,0.01875));} 24% {background:linear-gradient(to right, rgba(0,0,255,0.225), rgba(255,0,0,0.0375));} 26% {background:linear-gradient(to right, rgba(0,0,255,0.24375), rgba(255,0,0,0.05625));} 28% {background:linear-gradient(to right, rgba(0,0,255,0.2625), rgba(255,0,0,0.075));} 30% {background:linear-gradient(to right, rgba(0,0,255,0.28125), rgba(255,0,0,0.09375));} 32% {background:linear-gradient(to right, rgba(0,0,255,0.3), rgba(255,0,0,0.1125));} 34% {background:linear-gradient(to right, rgba(0,0,255,0.31875), rgba(255,0,0,0.13125));} 36% {background:linear-gradient(to right, rgba(0,0,255,0.3375), rgba(255,0,0,0.15));} 38% {background:linear-gradient(to right, rgba(0,0,255,0.35625), rgba(255,0,0,0.16875));} 40% {background:linear-gradient(to right, rgba(0,0,255,0.375), rgba(255,0,0,0.1875));} 42% {background:linear-gradient(to right, rgba(0,0,255,0.39375), rgba(255,0,0,0.20625));} 44% {background:linear-gradient(to right, rgba(0,0,255,0.4125), rgba(255,0,0,0.225));} 46% {background:linear-gradient(to right, rgba(0,0,255,0.43125),rgba(255,0,0,0.24375));} 48% {background:linear-gradient(to right, rgba(0,0,255,0.45), rgba(255,0,0,0.2625));} 50% {background:linear-gradient(to right, rgba(0,0,255,0.46875), rgba(255,0,0,0.28125));} 52% {background:linear-gradient(to right, rgba(0,0,255,0.4875), rgba(255,0,0,0.3));} 54% {background:linear-gradient(to right, rgba(0,0,255,0.50625), rgba(255,0,0,0.31875));} 56% {background:linear-gradient(to right, rgba(0,0,255,0.525), rgba(255,0,0,0.3375));} 58% {background:linear-gradient(to right, rgba(0,0,255,0.54375), rgba(255,0,0,0.35625));} 60% {background:linear-gradient(to right, rgba(0,0,255,0.5625), rgba(255,0,0,0.375));} 62% {background:linear-gradient(to right, rgba(0,0,255,0.58125), rgba(255,0,0,0.39375));} 64% {background:linear-gradient(to right,rgba(0,0,255,0.6), rgba(255,0,0,0.4125));} 66% {background:linear-gradient(to right, rgba(0,0,255,0.61875), rgba(255,0,0,0.43125));} 68% {background:linear-gradient(to right, rgba(0,0,255,0.6375), rgba(255,0,0,0.45));} 70% {background:linear-gradient(to right, rgba(0,0,255,0.65625), rgba(255,0,0,0.46875));} 72% {background:linear-gradient(to right, rgba(0,0,255,0.675), rgba(255,0,0,0.4875));} 74% {background:linear-gradient(to right, rgba(0,0,255,0.69375), rgba(255,0,0,0.50625));} 76% {background:linear-gradient(to right, rgba(0,0,255,0.7125), rgba(255,0,0,0.525));} 78% {background:linear-gradient(to right, rgba(0,0,255,0.73125),,rgba(255,0,0,0.54375));} 80% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.5625));} 82% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.58125));} 84% {background:linear-gradient(to right, rgba(0,0,255,0.75),rgba(255,0,0,0.6));} 86% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.61875));} 88% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.6375));} 90% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.65625));} 92% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.675));} 94% {background:linear-gradient(to right, rgba(0,0,255,0.75),rgba(255,0,0,0.69375));} 96% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.7125));} 98% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.73125),);} 100% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75));} } <div class="contener" style=""> <div class="ed"></div> </div>