<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>未使用setCustomValidity()方法</title>
</head>
<body>
<form name="test" action="" method="post">
<input id="input" type="text" required="required" placeholder="请输入4-11位字母加数字的密码" pattern="^(?![0-9]+$)(?![a-zA-Z]+$)[0-9a-zA-Z]{4,14}$" oninput="this.setCustomValidity('')">
<input type="submit" onclick="setMyText()">
</form>
<script type="text/javascript">
function setMyText(){
var obj = document.getElementById("input");
if (obj.validity.patternMismatch === true) {
obj.setCustomValidity("密码是必填的");
} else {
obj.setCustomValidity('');
}
}
</script>
</body>
</html>