代码：
html表单代码：
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>回车键实现登录方法</title>
<script src="js/jquery-latest.min.js"></script>
</head>
<body>
<form id="loginForm">
<div class="form-group row">
<p>用户名</p>
<input style=" 100%;" type="text" class="form-control" id="login" placeholder="请输入帐号">
</div>
<input type="button" class="btn btn-success" onclick="loginSubmit()" value="登陆">
</form>
</body>
</html>
要先引入JQuery文件（最新的jQuery版本更好）
Jq代码：
<javascript>
$("#loginForm").keydown(function (e){
var theEvent = window.event || e;
var code = theEvent.keyCode || theEvent.which;
if(code == 13){//回车键码是13
loginSubmit();
}
})
function loginSubmit(){
alert("调用成功");
}
</javascript>