场景
. vue对前端开发的友好是jQ比拟不了的
分析
. v-model可以实现表单元素和应用状态的双向绑定
. v-show,v-if 配合v-model可以快捷实现一些简单功能
. v-show 实现的原理是 display:none
. v-if 元素存在或者不存在
实例
. textarea如果为空 则提示输入内容；否则去掉提示 展示输出按钮
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>vue show</title>
<script src="vue.js"></script>
<script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js"></script>
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css"
integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap-theme.min.css"
integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
<script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"
integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
crossorigin="anonymous"></script>
</head>
<body>
<div id="app" class="col-md-8 col-md-offset-2">
<form action="">
<div class="has-error" v-show="!message"><span class="control-label">请输入信息</span></div>
<div class="form-group">
<label for="content"></label>
<textarea name="content" id="content" cols="30" rows="10" v-model="message"></textarea>
</div>
<div class="form-group" v-show="message">
<button>提交按钮</button>
</div>
</form>
{{ $data }}
</div>
<script>
new Vue({
el: '#app',
data: {
message: ''
}
});
</script>
</body>
</html>