伪类中的valid和invalid_html/css_WEB-ITnose
在CSS3之前,我们在处理输入框的判断输入是否正确时,都会做相应的输入样式来提醒用户输入的正确性.而CSS3中已经增加了这一特性,valid和invalid这两个伪类.这两个主要作用在input输入框上.
我们来看看一个提交建议的实例界面很简单主要是:
结构代码里,用户名是必须要输入的,email是可选的,建议内容字符在4到20个字符之间(这里配合的pattern属性的用法).
我们接着写出CSS代码,其实就是改变其输入框的背景.
input:valid{
background-color: #44b549;
}
input:invalid {
background-color: crimson;
}
最后的界面效果如下:
大家试着输入相应的匹配文字或者不匹配的文字,看看效果如何!看看是否对比有很大帮助!
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