<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div>
<button id="myBtn">改变username</button>
<input type="text" id="myInput">
<h1 id="myTitle"></h1>
</div>
</body>
<script>
let userinfo = {
username: '小明',
};
//开始监控
watcher();
function watcher() {
Object.defineProperty(userinfo, "username", {
set(value) {
updateDom(value);
},
get(val) {
return val;
},
});
}
//更新dom数据
function updateDom(value) {
document.querySelector('#myInput').value = value;
document.querySelector('#myTitle').innerHTML = value;
}
//给input绑定input事件，实时修改username的值
document.querySelector('#myInput').oninput = function (e) {
let value = e.target.value;
userinfo.username = value;
}
//给button绑定点击事件，修改username的值
document.querySelector('#myBtn').onclick = function () {
let value = '小明';
userinfo.username = value;
}
</script>
</html>
