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:
*{ 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; }
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:
*{ 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; }
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,谢谢大家对考高分网的支持。



