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将时间转换为关键帧动画百分比

css-animations css html javascript

1.21 gigawatts · 技术社区 · 6 年前

我正在制作一个动画,我想知道关键帧是如何融入其中的。

我想显示一个元素3秒钟,淡出1秒,等待3秒钟,淡入1秒,可见3秒钟。所以总共8秒(3+1+3+1)。

我不知道如何把它写成关键帧。我的动画中有备用集,因为它使用的是百分比。以下是迄今为止我所拥有的:

time = 0;
window.addEventListener("load", function() {
   setInterval(function() {
    var label = document.getElementById("label");
    
    if (time==0) {
      label.innerHTML = ++time;
    }
    else {
      label.innerHTML = ++time;
    }
    if (time>=8) time = 0;
    
   }, 1000);
})

* {
		margin: 0;
		padding: 0;
    font-family:sans-serif;
	}
	#Icons_A0 {
		position: absolute;
		box-sizing: border-box;
		transform: translateX(-50%) translateY(-50%);
		left: 50%;
		top: 50%;
		border: 1px solid #A1A1A1;
		background: #E5E5E5;
		width: 234px;
		height: 238px;
		background-color: rgba(255,255,255,1);
		overflow: hidden;
		opacity: 1;
	}
	#Rectangle_175 {
		opacity: 1;
		fill: rgba(75,134,193,1);
		stroke: rgb(84, 75, 193);
		stroke-width: 4px;
		stroke-linejoin: miter;
		stroke-linecap: butt;
		stroke-miterlimit: 4;
		shape-rendering: auto;
	}
	.Rectangle_175 {
		position: absolute;
		overflow: visible;
		width: 134.35028076171875px;
		height: 134.3502655029297px;
		left: 49.825px;
		top: 76.825px;
		transform: rotate(45deg);
		transform-origin: left;
	}
	#Ellipse_49 {
		opacity: 1;
		fill: rgba(180,180,180,1);
		stroke: rgb(112, 112, 112);
		stroke-width: 1px;
		stroke-linejoin: miter;
		stroke-linecap: butt;
		stroke-miterlimit: 4;
		shape-rendering: auto;
	}
	.Ellipse_49 {
		position: absolute;
		overflow: visible;
		width: 56px;
		height: 56px;
		left: 72px;
		top: 51px;
    animation: fadein 8s linear 0s infinite alternate;
	}
	@keyframes fadein {
	
		0% {
			opacity: 1;
		}
		20% {
			opacity: 1;
		}
		30% {
			opacity: 0;
		}
		60% {
			opacity: 0;
		}
		70% {
			opacity: 1;
		}
		100% {
			opacity: 1;
		}
	
	}

<div id="Icons_A0">
	<svg data-name="Rectangle 175" data-type="Rectangle" class="Rectangle_175">
		<rect id="Rectangle_175" rx="0" ry="0" x="0" y="0" width="120" height="70">
		</rect>
	</svg>
	<svg class="Ellipse_49">
		<ellipse id="Ellipse_49" rx="28" ry="28" cx="28" cy="28">
		</ellipse>
	</svg>
  <span id="label"></span>
</div>

3 回复 | 直到 6 年前

1.21 gigawatts 6 年前

如果我正确理解您的问题,则可以通过以下关键帧集实现:

@keyframes fadein {
  0% {
    opacity: 1;

  }
  37.5% {
    /* 3 / 8 */
    opacity: 1; 
  }
  50% {
    /* (3 + 1) / 8 */
    opacity: 0.0; 
  }
  87.5% {
    /* (3 + 1 + 3) / 8 */
    opacity: 0.0; 
  }
  100% {
    opacity: 1; 
  }
}

注释显示了如何根据您的需求计算不同关键帧的百分比。要做的另一个关键更改是删除 alternate 动画规则中的行为,以确保动画循环按要求以一致的方式重复:

/* remove alternate */
animation: fadein 8s linear 0s infinite;

下面是一个简化的代码副本,用于隔离动画圈:

function animationListener(event) {
  var type = event.type;
  var label = type;
  
  if (type=="animationiteration") {
    if (app.interval!=null) {
      clearInterval(app.interval);
    }
    app.time = 0;
    app.startTime = new Date().getTime();
    app.interval = setInterval(intervalFunction, 1000);
    intervalFunction();
    label = "iteration";
  }
  else if (type=="animationstart") {
    label = "start";
  }
  else if (type=="animationend") {
    label = "end";
  }
  
  app.stateLabel.innerHTML = label;
}

function intervalFunction() {
  var time = new Date().getTime();
  app.timeLabel.innerHTML = Math.round((time - app.startTime)/1000);
  app.keyframeLabel.innerHTML = window.getComputedStyle(app.ellipse).content;
}

function loadHandler() {
  app.ellipse = document.getElementById("Ellipse_49").parentNode;
  app.stateLabel = document.getElementById("stateLabel");
  app.timeLabel = document.getElementById("timeLabel");
  app.keyframeLabel = document.getElementById("keyframeLabel");
  
  app.ellipse.addEventListener("animationiteration", animationListener);
  app.ellipse.addEventListener("animationend", animationListener);
  app.ellipse.addEventListener("animationstart", animationListener);
}

document.addEventListener("DOMContentLoaded", loadHandler);
var app = {};

* {
  font-family: sans-serif;
  font-size: 11px;
  letter-spacing: .6px;
}

#Ellipse_49 {
  opacity: 1;
  fill: rgba(180, 180, 180, 1);
  stroke: rgb(112, 112, 112);
  stroke-width: 1px;
  stroke-linejoin: miter;
  stroke-linecap: butt;
  stroke-miterlimit: 4;
  shape-rendering: auto;
}

.Ellipse_49 {
  position: absolute;
  overflow: visible;
  width: 56px;
  height: 56px;
  left: 72px;
  top: 51px;
  
  /* remove alternate */
  animation: fadein 8s linear 0s infinite;
}

#container {
   top: 130px;
   left: 10px;
   position: relative;
   display: block;
   align-items: center;
   
}

label {
  width: 80px;
  display: inline-block;
}

@keyframes fadein {
  0% {
    opacity: 1;
    content: "show";
  }
  37.5% {
    /* 3 / 8 */
    opacity: 1;
    content: "fade out";
  }
  50% {
    /* (3 + 1) / 8 */
    opacity: 0.0;
    content: "wait";
  }
  87.5% {
    /* (3 + 1 + 3) / 8 */
    opacity: 0.0;
    content: "fade in";
  }
  100% {
    opacity: 1;
    content: "show";
  }
}

<svg class="Ellipse_49">
		<ellipse id="Ellipse_49" rx="28" ry="28" cx="28" cy="28">
		</ellipse>
</svg>


<div id="container">
  <label>time: </label>
  <span id="timeLabel"></span>
  <br>
  <label>state: </label>
  <span id="stateLabel"></span>
  <br>
  <label>key frame: </label>
  <span id="keyframeLabel"></span>
</div>

Frederick Brummer 6 年前

如果你的总长度是8秒,你只需要把它转换成百分比,那么数学就非常简单: 100/8=12.5

所以,你的关键帧会出现在:

1 sec : 12.5 * 1 = 12.5%
4 sec : 12.5 * 4 = 50%
7 sec : 12.5 * 7 = 87.5%
8 sec : 12.5 * 8 = 100%

1.21 gigawatts 6 年前

在此处添加@dacredenny的答案,以便我修改它并添加注释。

function animationListener(event) {
  var type = event.type;
  var label = type;
  
  if (type=="animationiteration") {
    if (app.interval!=null) {
      clearInterval(app.interval);
    }
    app.time = 0;
    app.startTime = new Date().getTime();
    app.interval = setInterval(intervalFunction, 15);
    intervalFunction();
    label = "iteration";
  }
  else if (type=="animationstart") {
    label = "start";
  }
  else if (type=="animationend") {
    label = "end";
  }
  
  app.stateLabel.innerHTML = label;
}

function intervalFunction() {
  var currentTime = new Date().getTime();
  var time = (currentTime - app.startTime)/1000;
  var duration = parseFloat(window.getComputedStyle(app.ellipse).animationDuration);
  var maxValue = 100;
  var position = ((time * maxValue)/duration);
  
  app.timeLabel.innerHTML = Math.round(time);
  app.keyframeLabel.innerHTML = window.getComputedStyle(app.ellipse).content;
  app.timelineRange.value = position;
  app.positionLabel.innerHTML = Math.round(position) + "%";
}

function loadHandler() {
  app.ellipse = document.getElementById("Ellipse_49").parentNode;
  app.stateLabel = document.getElementById("stateLabel");
  app.timeLabel = document.getElementById("timeLabel");
  app.keyframeLabel = document.getElementById("keyframeLabel");
  app.timelineRange = document.getElementById("timelineRange");
  app.positionLabel = document.getElementById("positionLabel");
  
  app.ellipse.addEventListener("animationiteration", animationListener);
  app.ellipse.addEventListener("animationend", animationListener);
  app.ellipse.addEventListener("animationstart", animationListener);
}

document.addEventListener("DOMContentLoaded", loadHandler);
var app = {};

* {
  font-family: sans-serif;
  font-size: 11px;
  letter-spacing: .6px;
}

@keyframes fadein {
  0% {
    opacity: 1;
    content: "show";
  }
  37.5% {
    /* 3 / 8 */
    opacity: 1;
    content: "fade out";
  }
  50% {
    /* (3 + 1) / 8 */
    opacity: 0.0;
    content: "wait";
  }
  87.5% {
    /* (3 + 1 + 3) / 8 */
    opacity: 0.0;
    content: "fade in";
  }
  100% {
    opacity: 1;
    content: "show";
  }
}

#Ellipse_49 {
  opacity: 1;
  fill: rgba(180, 180, 180, 1);
  stroke: rgb(112, 112, 112);
  stroke-width: 1px;
  stroke-linejoin: miter;
  stroke-linecap: butt;
  stroke-miterlimit: 4;
  shape-rendering: auto;
}

.Ellipse_49 {
  position: absolute;
  overflow: visible;
  width: 50px;
  height: 50px;
  left: 20px;
  top: 50px;
  
  /* remove alternate */
  animation: fadein 4s linear 0s infinite;
}

#container {
   top: 130px;
   left: 10px;
   position: relative;
   display: block;
}

label {
  width: 80px;
  display: inline-block;
}

input[type=range] {
  outline: 0px solid red;
  display: block;
  width: 90%;
  margin-left: 0;
}
input[type=range]::-webkit-slider-runnable-track {
  width: 100%;
  height: 8.4px;
  cursor: pointer;
  box-shadow: 0px 0px 0px #000000, 0px 0px 0px #0d0d0d;
  background: rgb(255,255,255);
}

<svg class="Ellipse_49">
		<ellipse id="Ellipse_49" rx="28" ry="28" cx="28" cy="28">
		</ellipse>
</svg>


<div id="container">
  <input id="timelineRange" type="range" value="0" min="0" max="100">
  <br>
  
  <label>time: </label>
  <span id="timeLabel"></span>
  <br>
  <label>position: </label>
  <span id="positionLabel"></span>
  <br>
  <label>state: </label>
  <span id="stateLabel"></span>
  <br>
  <label>key frame: </label>
  <span id="keyframeLabel"></span>
  <br>
  <br>
</div>