按钮（Buttons）

本章介绍Bootstrap按钮的使用年限和示例。 任何给定.btn类的.btn都会继承带圆角的灰色按钮的默认外观。 但是，Bootstrap提供了样式按钮的一些选项，如下表所示 -

以下示例演示了上述所有按钮类 -

<!-- Standard button -->
<button type = "button" class = "btn btn-default">Default Button</button>
<!-- Provides extra visual weight and identifies the primary action in a set of buttons -->
<button type = "button" class = "btn btn-primary">Primary Button</button>
<!-- Indicates a successful or positive action -->
<button type = "button" class = "btn btn-success">Success Button</button>
<!-- Contextual button for informational alert messages -->
<button type = "button" class = "btn btn-info">Info Button</button>
<!-- Indicates caution should be taken with this action -->
<button type = "button" class = "btn btn-warning">Warning Button</button>
<!-- Indicates a dangerous or potentially negative action -->
<button type = "button" class = "btn btn-danger">Danger Button</button>
<!-- Deemphasize a button by making it look like a link while maintaining button behavior -->
<button type = "button" class = "btn btn-link">Link Button</button>

按钮大小

下表总结了用于获取各种尺寸按钮的类 -

以下示例演示了这一点 -

<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Large Primary button
   </button>
   <button type = "button" class = "btn btn-default btn-lg">
      Large button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary">
      Default size Primary button
   </button>
   <button type = "button" class = "btn btn-default">
      Default size button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary btn-sm">
      Small Primary button
   </button>
   <button type = "button" class = "btn btn-default btn-sm">
      Small button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary btn-xs">
      Extra small Primary button
   </button>
   <button type = "button" class = "btn btn-default btn-xs">
      Extra small button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary btn-lg btn-block">
      Block level Primary button
   </button>
   <button type = "button" class = "btn btn-default btn-lg btn-block">
      Block level button
   </button>
</p>

按钮状态

Bootstrap提供了一些类，允许您将按钮的状态更改为活动，禁用等，以下各节将讨论这些类。

Active State

活动时，按钮将显示为按下（背景较暗，边框较暗，内嵌阴影）。 下表总结了用于使按钮元素和锚元素处于活动状态的类 -

以下示例演示了这一点 -

<p>
   <button type = "button" class = "btn btn-default btn-lg ">
      Default Button
   </button>
   <button type = "button" class = "btn btn-default btn-lg active">
      Active Button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Primary button
   </button>
   <button type = "button" class = "btn btn-primary btn-lg active">
      Active Primary button
   </button>
</p>

Disabled State

禁用按钮时，它将淡入淡出50％，并失去渐变。

下表总结了用于禁用按钮元素和锚元素的类 -

以下示例演示了这一点 -

<p>
   <button type = "button" class = "btn btn-default btn-lg">
      Default Button
   </button>
   <button type = "button" class = "btn btn-default btn-lg" disabled = "disabled">
      Disabled Button
   </button>
</p>
<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Primary button
   </button>
   <button type = "button" class = "btn btn-primary btn-lg" disabled = "disabled">
      Disabled Primary button
   </button>
</p>
<p>
   <a href = "#" class = "btn btn-default btn-lg" role = "button">
      Link
   </a>
   <a href = "#" class = "btn btn-default btn-lg disabled" role = "button">
      Disabled Link
   </a>
</p>
<p>
   <a href = "#" class = "btn btn-primary btn-lg" role = "button">
      Primary link
   </a>
   <a href = "#" class = "btn btn-primary btn-lg disabled" role = "button">
      Disabled Primary link
   </a>
</p>

按钮标签

您可以将按钮类与，或《input》元素一起使用。 但建议您将其与元素一起使用，以避免跨浏览器不一致问题。

以下示例演示了这一点 -

<a class = "btn btn-default" href = "#" role = "button">Link</a>
<button class = "btn btn-default" type = "submit">Button</button>
<input class = "btn btn-default" type = "button" value = "Input">
<input class = "btn btn-default" type = "submit" value = "Submit">