Posted in Javascript onSeptember 01, 2016
在刚开始没有给输入框添加焦点之前，没有任何效果。见下图：
然后点击其中任何一个，焦点就会触发一个动画，动画的结果见图二：
中间的输入登录密码文字，会自动添加到顶部（原谅我没有截取到动画过程的图片）。
我测试了一下，这样的效果只有高级浏览器支持（IE只有IE10、IE11、Edge支持）。
下面我来把代码贴上来，原理很简单，就是通过事件触发类名的增加和删除。具体的动画由CSS3来实现，这也是为什么低级浏览器不支持的原因。
原生JS实现示例：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
*{
padding: 0;
margin: 0;
}
.demo{
border: 1px solid gray;
width: 300px;
height: 200px;
position: relative;
left: 200px;
top: 200px;
-webkit-transition: all 0.3s linear;
-moz-transition: all 0.3s linear;
-ms-transition: all 0.3s linear;
-o-transition: all 0.3s linear;
transition: all 0.3s linear;
}
.demo input{
width: 200px;
height: 100px;
position: absolute;
left: 50px;
top: 50px;
-webkit-transition: all 0.3s linear;
-moz-transition: all 0.3s linear;
-ms-transition: all 0.3s linear;
-o-transition: all 0.3s linear;
transition: all 0.3s linear;
}
.demo label{
position: absolute;
top: 100px;
left:80px;
font-size: 14px;
-webkit-transition: all 0.3s linear;
-moz-transition: all 0.3s linear;
-ms-transition: all 0.3s linear;
-o-transition: all 0.3s linear;
transition: all 0.3s linear;
}
.activeDemo{
border: 1px #fd715a solid;
-webkit-transition: all 0.3s ease;
-moz-transition: all 0.3s ease;
-ms-transition: all 0.3s ease;
-o-transition: all 0.3s ease;
transition: all 0.3s ease;
}
.activeInput{
border: 1px #fd715a solid;
-webkit-transition: all 0.3s ease;
-moz-transition: all 0.3s ease;
-ms-transition: all 0.3s ease;
-o-transition: all 0.3s ease;
transition: all 0.3s ease;
}
.activeLabel{
font-size: 10px;
color: #fd715a;
background: white;
-webkit-transform: translate(-20px, -58px);
-moz-transform: translate(-20px, -58px);
-ms-transform: translate(-20px, -58px);
-o-transform: translate(-20px, -58px);
transform: translate(-20px, -58px);
-webkit-transition: all 0.3s linear;
-moz-transition: all 0.3s linear;
-ms-transition: all 0.3 linear;
-o-transition: all 0.3s linear;
transition: all 0.3s linear;
}
</style>
</head>
<body>
<div class="demo">
<input type="text" id="inputDemo"/>
<label for="inputDemo">请输入内容</label>
</div>
</body>
<script>
var addEvent= function (obj,event,callback) {
if(obj.addEventListener){
obj.addEventListener(event,callback)
}else if(obj.attachEvent){
obj.attachEvent('on'+event,callback)
}
};
var demo=document.querySelector(".demo");
var input=document.querySelector("#inputDemo");
var label=document.querySelector(".demo label");
addEvent(input,"focus", function () {
demo.className+=" activeDemo";
this.className+=" activeInput";
label.className+=" activeLabel";
});
addEvent(input,'blur', function () {
this.className=this.className.replace(/\s*activeInput\s*/,' ');
label.className=label.className.replace(/\s*activeLabel\s*/,' ');
demo.className=demo.className.replace(/\s*activeDemo\s*/,' ');
})
</script>
</html>
下面是用Angular实现的一个简单的效果，原理很简单，就是在指令中通操作DOM来实现动画。
Angularjs实现示例：
<!DOCTYPE html>
<html lang="en" ng-app="formAnimation">
<head>
<meta charset="UTF-8">
<title></title>
<script src="lib/angular.min.js" type="text/javascript"></script>
<script src="lib/angular-animate.js" type="text/javascript"></script>
<style>
*{
padding: 0;
margin: 0;
}
.container{
width: 445px;
height: 370px;
border-left: 10px solid #d4d4d4;
position: relative;
left: 100px;
top: 100px;
}
.container input{
position: absolute;
top: 100px;
left: 25px;
height: 40px;
width: 385px;
}
.container span{
width: 80px;
height: 25px;
font-size: 10px;
background: rgb(237,97,83);
color: white;
position: absolute;
left: 300px;
top: 109px;
line-height: 25px;
text-align: center;
}
.container .labelStyle{
position: absolute;
left: 45px;
top: 115px;
font-size: 14px;
color: #929292;
z-index: 999;
font: "Helvetica Neue", Helvetica, Arial, sans-serif;
-webkit-transition: all 0.2s ease;
-moz-transition: all 0.2s ease;
-ms-transition: all 0.2s ease;
-o-transition: all 0.2s ease;
transition: all 0.2s ease;
}
.inputActive{
border: 2px solid rgb(237,97,90);
-webkit-transition: all 0.2s ease;
-moz-transition: all 0.2s ease;
-ms-transition: all 0.2s ease;
-o-transition: all 0.2s ease;
transition: all 0.2s ease;
}
.labelActive{
position: absolute;
left: 45px;
top: 115px;
z-index: 999;
background: white;
border: 2px solid white;
color: rgb(237,97,90);
font-size: 10px;
-webkit-transform: translate(-10px, -23px);
-moz-transform: translate(-10px, -23px);
-ms-transform: translate(-10px, -23px);
-o-transform: translate(-10px, -23px);
transform: translate(-10px, -23px);
-webkit-transition: all 0.2s ease;
-moz-transition: all 0.2s ease;
-ms-transition: all 0.2s ease;
-o-transition: all 0.2s ease;
transition: all 0.2s ease;
}
</style>
</head>
<body ng-controller="formAnimationController">
<form action="" class="container" form-animation>
<label for="inputDemo" class="labelStyle">请输入内容</label>
<input type="text" id="inputDemo" />
<span>请填写内容</span>
</form>
</body>
<script>
angular.module('formAnimation',[])
.controller('formAnimationController', function () {
})
.directive('formAnimation',['$animate', function ($animate) {
return {
restrict:'EA',
link: function (scope, element, attr) {
element.find("input").on('focus', function () {
element.find("input").addClass("inputActive");
element.find("label").removeClass("labelStyle").addClass("labelActive")
});
element.find("input").on('blur', function () {
element.find("input").removeClass("inputActive");
element.find("label").removeClass("labelActive").addClass("labelStyle");
})
}
}
}])
</script>
</html>
总结
上面的两种方式只是体现了一下实现的方式，具体的实现样式大家可以可以参照效果图，调节CSS样式。希望这篇文章的内容对大家学习Angularjs和JS能有所帮助，如果有问题可以留言交流，谢谢大家对三水点靠木的支持。
利用Angularjs和原生JS分别实现动态效果的输入框
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MakingChoice声明：登载此文出于传递更多信息之目的，并不意味着赞同其观点或证实其描述。
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