Bootstrap 表单
Bootstrap Forms
在Bootstrap中，存在三种类型的表单布局:
垂直形式(这是默认设置)
水平形式
内联表格
Bootstrap表单规则
这3种表单布局有三个标准规则:
始终使用<form role="form">(有助于提高使用屏幕阅读器的用户的可访问性)
将标签和表单控件包装在<div class="form-group">中(需要最佳间距)
将.form-control类添加到所有文本<input>，<textarea>和<select>元素
1)Bootstrap 垂直格式(默认)
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap example</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"/>
</head>
<body>
<div class="container">
<h1>Vertical Form Example</h1>
<form style="width:300px">
<div class="form-group">
<label for="exampleInputEmail1">Email address</label>
<input type="email" class="form-control" id="exampleInputEmail1" placeholder="Email">
</div>
<div class="form-group">
<label for="exampleInputPassword1">Password</label>
<input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
</div>
<button type="submit" class="btn btn-default">Login</button>
</form>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
</body>
</html>
2)Bootstrap内联表单
在Bootstrap内联表单中，所有元素都是内联的，左对齐，并且标签在旁边。
此示例仅适用于视口内宽度至少为768px的表单!
示例:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<h2>Inline form Example</h2>
<form class="form-inline" role="form">
<form style="width:300px">
<div class="form-group">
<label for="exampleInputEmail1">Email address</label>
<input type="email" class="form-control" id="exampleInputEmail1" placeholder="Email">
</div>
<div class="form-group">
<label for="exampleInputPassword1">Password</label>
<input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
</div>
<button type="submit" class="btn btn-default">Login</button>
</form>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</body>
</html>
3)Bootstrap水平表格
如果要创建水平表格，则必须添加一些其他规则。
其他水平形式的规则:
将.form-horizontal类添加到<form>元素
将.control-label类添加到所有<label>元素
示例:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<h2>Horizontal form Example</h2>
<form class="form-horizontal" role="form">
<form style="width:300px">
<div class="form-group">
<label class="control-label col-sm-2" for="email">Email:</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="email" placeholder="Enter email">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-2" for="pwd">Password:</label>
<div class="col-sm-10">
<input type="password" class="form-control" id="pwd" placeholder="Enter password">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="submit" class="btn btn-default">Submit</button>
</div>
</div>
</form>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</body>
</html>
Bootstrap 4表单
在Bootstrap4中，表单控件会通过Bootstrap自动接收某些全局样式。
.form-control类的所有文本<input>，<textarea>和<select>元素的宽度均为100％。
堆叠(全角)形式:
Bootstrap 4提供了全角堆叠形式。
示例:
让我们以创建具有两个输入字段，一个复选框和一个提交按钮的堆叠形式为例。
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.6/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>Stacked form</h2>
<form>
<div class="form-group">
<label for="email">Email:</label>
<input type="email" class="form-control" id="email" placeholder="Enter email">
</div>
<div class="form-group">
<label for="pwd">Password:</label>
<input type="password" class="form-control" id="pwd" placeholder="Enter password">
</div>
<div class="form-check">
<label class="form-check-label">
<input class="form-check-input" type="checkbox"> Remember me
</label>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>
</div>
</body>
</html>
