一、前言
現在開始介紹bootstrap的表單(forms)樣式。
二、源碼
1、forms.less
1.1、forms.less源碼
//
// Forms(表單)
// --------------------------------------------------
// Normalize non-controls(定製非表單控件)
//
// Restyle and baseline non-control form elements.
fieldset {
padding: 0;
margin: 0;
border: 0;
// Chrome and Firefox set a `min-width: min-content;` on fieldsets,
// so we reset that to ensure it behaves more like a standard block element.
// See https://github.com/twbs/bootstrap/issues/12359.
min-width: 0;
}
legend {
display: block;
width: 100%;
padding: 0;
margin-bottom: @line-height-computed;
font-size: (@font-size-base * 1.5);
line-height: inherit;
color: @legend-color;
border: 0;
border-bottom: 1px solid @legend-border-color;
}
label {
display: inline-block;
max-width: 100%; // Force IE8 to wrap long content (see https://github.com/twbs/bootstrap/issues/13141)
margin-bottom: 5px;
font-weight: bold;
}
// Normalize form controls(定製表單控件)
//
// While most of our form styles require extra classes, some basic normalization
// is required to ensure optimum display with or without those classes to better
// address browser inconsistencies.
// Override content-box in Normalize (* isn't specific enough)
input[type="search"] {
.box-sizing(border-box);
}
// Position radios and checkboxes better
input[type="radio"],
input[type="checkbox"] {
margin: 4px 0 0;
margin-top: 1px \9; // IE8-9
line-height: normal;
}
input[type="file"] {
display: block;
}
// Make range inputs behave like textual form controls
input[type="range"] {
display: block;
width: 100%;
}
// Make multiple select elements height not fixed
select[multiple],
select[size] {
height: auto;
}
// Focus for file, radio, and checkbox
input[type="file"]:focus,
input[type="radio"]:focus,
input[type="checkbox"]:focus {
.tab-focus();
}
// Adjust output element
output {
display: block;
padding-top: (@padding-base-vertical + 1);
font-size: @font-size-base;
line-height: @line-height-base;
color: @input-color;
}
// Common form controls(普通的表單控件)
//
// Shared size and type resets for form controls. Apply `.form-control` to any
// of the following form controls:
//
// select
// textarea
// input[type="text"]
// input[type="password"]
// input[type="datetime"]
// input[type="datetime-local"]
// input[type="date"]
// input[type="month"]
// input[type="time"]
// input[type="week"]
// input[type="number"]
// input[type="email"]
// input[type="url"]
// input[type="search"]
// input[type="tel"]
// input[type="color"]
.form-control {
display: block;
width: 100%;
height: @input-height-base; // Make inputs at least the height of their button counterpart (base line-height + padding + border)
padding: @padding-base-vertical @padding-base-horizontal;
font-size: @font-size-base;
line-height: @line-height-base;
color: @input-color;
background-color: @input-bg;
background-image: none; // Reset unusual Firefox-on-Android default style; see https://github.com/necolas/normalize.css/issues/214
border: 1px solid @input-border;
border-radius: @input-border-radius; // Note: This has no effect on <select>s in some browsers, due to the limited stylability of <select>s in CSS.
.box-shadow(inset 0 1px 1px rgba(0,0,0,.075));
.transition(~"border-color ease-in-out .15s, box-shadow ease-in-out .15s");
// Customize the `:focus` state to imitate native WebKit styles.
.form-control-focus();
// Placeholder
.placeholder();
// Unstyle the caret on `<select>`s in IE10+.
&::-ms-expand {
border: 0;
background-color: transparent;
}
// Disabled and read-only inputs
//
// HTML5 says that controls under a fieldset > legend:first-child won't be
// disabled if the fieldset is disabled. Due to implementation difficulty, we
// don't honor that edge case; we style them as disabled anyway.
&[disabled],
&[readonly],
fieldset[disabled] & {
background-color: @input-bg-disabled;
opacity: 1; // iOS fix for unreadable disabled content; see https://github.com/twbs/bootstrap/issues/11655
}
&[disabled],
fieldset[disabled] & {
cursor: @cursor-disabled;
}
// Reset height for `textarea`s
textarea& {
height: auto;
}
}
// Search inputs in iOS
//
// This overrides the extra rounded corners on search inputs in iOS so that our
// `.form-control` class can properly style them. Note that this cannot simply
// be added to `.form-control` as it's not specific enough. For details, see
// https://github.com/twbs/bootstrap/issues/11586.
input[type="search"] {
-webkit-appearance: none;
}
// Special styles for iOS temporal inputs
//
// In Mobile Safari, setting `display: block` on temporal inputs causes the
// text within the input to become vertically misaligned. As a workaround, we
// set a pixel line-height that matches the given height of the input, but only
// for Safari. See https://bugs.webkit.org/show_bug.cgi?id=139848
//
// Note that as of 9.3, iOS doesn't support `week`.
@media screen and (-webkit-min-device-pixel-ratio: 0) {
input[type="date"],
input[type="time"],
input[type="datetime-local"],
input[type="month"] {
&.form-control {
line-height: @input-height-base;
}
&.input-sm,
.input-group-sm & {
line-height: @input-height-small;
}
&.input-lg,
.input-group-lg & {
line-height: @input-height-large;
}
}
}
// Form groups(表單組)
//
// Designed to help with the organization and spacing of vertical forms. For
// horizontal forms, use the predefined grid classes.
.form-group {
margin-bottom: @form-group-margin-bottom;
}
// Checkboxes and radios(表單控件:複選框checkbox和單選框radio)
//
// Indent the labels to position radios/checkboxes as hanging controls.
.radio,
.checkbox {
position: relative;
display: block;
margin-top: 10px;
margin-bottom: 10px;
label {
min-height: @line-height-computed; // Ensure the input doesn't jump when there is no text
padding-left: 20px;
margin-bottom: 0;
font-weight: normal;
cursor: pointer;
}
}
.radio input[type="radio"],
.radio-inline input[type="radio"],
.checkbox input[type="checkbox"],
.checkbox-inline input[type="checkbox"] {
position: absolute;
margin-left: -20px;
margin-top: 4px \9;
}
.radio + .radio,
.checkbox + .checkbox {
margin-top: -5px; // Move up sibling radios or checkboxes for tighter spacing
}
// Radios and checkboxes on same line(複選框和單選框水平排列)
.radio-inline,
.checkbox-inline {
position: relative;
display: inline-block;
padding-left: 20px;
margin-bottom: 0;
vertical-align: middle;
font-weight: normal;
cursor: pointer;
}
.radio-inline + .radio-inline,
.checkbox-inline + .checkbox-inline {
margin-top: 0;
margin-left: 10px; // space out consecutive inline controls
}
// Apply same disabled cursor tweak as for inputs(添加disable樣式)
// Some special care is needed because <label>s don't inherit their parent's `cursor`.
//
// Note: Neither radios nor checkboxes can be readonly.
input[type="radio"],
input[type="checkbox"] {
&[disabled],
&.disabled,
fieldset[disabled] & {
cursor: @cursor-disabled;
}
}
// These classes are used directly on <label>s
.radio-inline,
.checkbox-inline {
&.disabled,
fieldset[disabled] & {
cursor: @cursor-disabled;
}
}
// These classes are used on elements with <label> descendants
.radio,
.checkbox {
&.disabled,
fieldset[disabled] & {
label {
cursor: @cursor-disabled;
}
}
}
// Static form control text(靜態表單控制文本)
//
// Apply class to a `p` element to make any string of text align with labels in
// a horizontal form layout.
.form-control-static {
// Size it appropriately next to real form controls
padding-top: (@padding-base-vertical + 1);
padding-bottom: (@padding-base-vertical + 1);
// Remove default margin from `p`
margin-bottom: 0;
min-height: (@line-height-computed + @font-size-base);
&.input-lg,
&.input-sm {
padding-left: 0;
padding-right: 0;
}
}
// Form control sizing(表單控件大小)
//
// Build on `.form-control` with modifier classes to decrease or increase the
// height and font-size of form controls.
//
// The `.form-group-* form-control` variations are sadly duplicated to avoid the
// issue documented in https://github.com/twbs/bootstrap/issues/15074.
.input-sm {
.input-size(@input-height-small; @padding-small-vertical; @padding-small-horizontal; @font-size-small; @line-height-small; @input-border-radius-small);
}
.form-group-sm {
.form-control {
height: @input-height-small;
padding: @padding-small-vertical @padding-small-horizontal;
font-size: @font-size-small;
line-height: @line-height-small;
border-radius: @input-border-radius-small;
}
select.form-control {
height: @input-height-small;
line-height: @input-height-small;
}
textarea.form-control,
select[multiple].form-control {
height: auto;
}
.form-control-static {
height: @input-height-small;
min-height: (@line-height-computed + @font-size-small);
padding: (@padding-small-vertical + 1) @padding-small-horizontal;
font-size: @font-size-small;
line-height: @line-height-small;
}
}
.input-lg {
.input-size(@input-height-large; @padding-large-vertical; @padding-large-horizontal; @font-size-large; @line-height-large; @input-border-radius-large);
}
.form-group-lg {
.form-control {
height: @input-height-large;
padding: @padding-large-vertical @padding-large-horizontal;
font-size: @font-size-large;
line-height: @line-height-large;
border-radius: @input-border-radius-large;
}
select.form-control {
height: @input-height-large;
line-height: @input-height-large;
}
textarea.form-control,
select[multiple].form-control {
height: auto;
}
.form-control-static {
height: @input-height-large;
min-height: (@line-height-computed + @font-size-large);
padding: (@padding-large-vertical + 1) @padding-large-horizontal;
font-size: @font-size-large;
line-height: @line-height-large;
}
}
// Form control feedback states(驗證狀態)
//
// Apply contextual and semantic states to individual form controls.
.has-feedback {
// Enable absolute positioning
position: relative;
// Ensure icons don't overlap text
.form-control {
padding-right: (@input-height-base * 1.25);
}
}
// Feedback icon (requires .glyphicon classes)
.form-control-feedback {
position: absolute;
top: 0;
right: 0;
z-index: 2; // Ensure icon is above input groups
display: block;
width: @input-height-base;
height: @input-height-base;
line-height: @input-height-base;
text-align: center;
pointer-events: none;
}
.input-lg + .form-control-feedback,
.input-group-lg + .form-control-feedback,
.form-group-lg .form-control + .form-control-feedback {
width: @input-height-large;
height: @input-height-large;
line-height: @input-height-large;
}
.input-sm + .form-control-feedback,
.input-group-sm + .form-control-feedback,
.form-group-sm .form-control + .form-control-feedback {
width: @input-height-small;
height: @input-height-small;
line-height: @input-height-small;
}
// Feedback states
.has-success {
.form-control-validation(@state-success-text; @state-success-text; @state-success-bg);
}
.has-warning {
.form-control-validation(@state-warning-text; @state-warning-text; @state-warning-bg);
}
.has-error {
.form-control-validation(@state-danger-text; @state-danger-text; @state-danger-bg);
}
// Reposition feedback icon if input has visible label above
.has-feedback label {
& ~ .form-control-feedback {
top: (@line-height-computed + 5); // Height of the `label` and its margin
}
&.sr-only ~ .form-control-feedback {
top: 0;
}
}
// Help text(提示信息)
//
// Apply to any element you wish to create light text for placement immediately
// below a form control. Use for general help, formatting, or instructional text.
.help-block {
display: block; // account for any element using help-block
margin-top: 5px;
margin-bottom: 10px;
color: lighten(@text-color, 25%); // lighten the text some for contrast
}
// Inline forms(內聯表單)
//
// Make forms appear inline(-block) by adding the `.form-inline` class. Inline
// forms begin stacked on extra small (mobile) devices and then go inline when
// viewports reach <768px.
//
// Requires wrapping inputs and labels with `.form-group` for proper display of
// default HTML form controls and our custom form controls (e.g., input groups).
//
// Heads up! This is mixin-ed into `.navbar-form` in navbars.less.
.form-inline {
// Kick in the inline
@media (min-width: @screen-sm-min) {
// Inline-block all the things for "inline"
.form-group {
display: inline-block;
margin-bottom: 0;
vertical-align: middle;
}
// In navbar-form, allow folks to *not* use `.form-group`
.form-control {
display: inline-block;
width: auto; // Prevent labels from stacking above inputs in `.form-group`
vertical-align: middle;
}
// Make static controls behave like regular ones
.form-control-static {
display: inline-block;
}
.input-group {
display: inline-table;
vertical-align: middle;
.input-group-addon,
.input-group-btn,
.form-control {
width: auto;
}
}
// Input groups need that 100% width though
.input-group > .form-control {
width: 100%;
}
.control-label {
margin-bottom: 0;
vertical-align: middle;
}
// Remove default margin on radios/checkboxes that were used for stacking, and
// then undo the floating of radios and checkboxes to match.
.radio,
.checkbox {
display: inline-block;
margin-top: 0;
margin-bottom: 0;
vertical-align: middle;
label {
padding-left: 0;
}
}
.radio input[type="radio"],
.checkbox input[type="checkbox"] {
position: relative;
margin-left: 0;
}
// Re-override the feedback icon.
.has-feedback .form-control-feedback {
top: 0;
}
}
}
// Horizontal forms(水平表單)
//
// Horizontal forms are built on grid classes and allow you to create forms with
// labels on the left and inputs on the right.
.form-horizontal {
// Consistent vertical alignment of radios and checkboxes
//
// Labels also get some reset styles, but that is scoped to a media query below.
.radio,
.checkbox,
.radio-inline,
.checkbox-inline {
margin-top: 0;
margin-bottom: 0;
padding-top: (@padding-base-vertical + 1); // Default padding plus a border
}
// Account for padding we're adding to ensure the alignment and of help text
// and other content below items
.radio,
.checkbox {
min-height: (@line-height-computed + (@padding-base-vertical + 1));
}
// Make form groups behave like rows
.form-group {
.make-row();
}
// Reset spacing and right align labels, but scope to media queries so that
// labels on narrow viewports stack the same as a default form example.
@media (min-width: @screen-sm-min) {
.control-label {
text-align: right;
margin-bottom: 0;
padding-top: (@padding-base-vertical + 1); // Default padding plus a border
}
}
// Validation states
//
// Reposition the icon because it's now within a grid column and columns have
// `position: relative;` on them. Also accounts for the grid gutter padding.
.has-feedback .form-control-feedback {
right: floor((@grid-gutter-width / 2));
}
// Form group sizes
//
// Quick utility class for applying `.input-lg` and `.input-sm` styles to the
// inputs and labels within a `.form-group`.
.form-group-lg {
@media (min-width: @screen-sm-min) {
.control-label {
padding-top: (@padding-large-vertical + 1);
font-size: @font-size-large;
}
}
}
.form-group-sm {
@media (min-width: @screen-sm-min) {
.control-label {
padding-top: (@padding-small-vertical + 1);
font-size: @font-size-small;
}
}
}
}1.2、forms.less應用
<!--默認垂直表單-->
<form role="form">
<div class="form-group">
<label for="name1">名稱</label>
<input type="text" class="form-control" id="name1" placeholder="請輸入名稱">
</div>
<div class="form-group">
<label for="inputfile1">文件輸入</label>
<input type="file" id="inputfile1">
<p class="help-block">這裏是塊級幫助文本的實例。</p>
</div>
<div class="checkbox">
<label>
<input type="checkbox">請打勾
</label>
</div>
<button type="submit" class="btn btn-default">提交</button>
</form>
<!--內聯表單-->
<form class="form-inline" role="form">
<div class="form-group">
<label class="sr-only" for="name2">名稱</label>
<input type="text" class="form-control" id="name2" placeholder="請輸入名稱">
</div>
<div class="form-group">
<label class="sr-only" for="inputfile2">文件輸入</label>
<input type="file" id="inputfile2">
</div>
<div class="checkbox">
<label>
<input type="checkbox">請打勾
</label>
</div>
<button type="submit" class="btn btn-default">提交</button>
</form>
<!--水平表單-->
<form class="form-horizontal" role="form">
<!--表單幫助文本-->
<label>幫助文本實例</label>
<input class="form-control" type="text" placeholder="">
<span class="help-block">一個較長的幫助文本塊，超過一行，
需要擴展到下一行。本實例中的幫助文本總共有兩行。</span>
<!--在一個水平表單內的表單標籤後放置純文本-->
<div class="form-group">
<label class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<p class="form-control-static">[email protected]</p>
</div>
</div>
<div class="form-group">
<label for="firstname" class="col-sm-2 control-label">名字</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="firstname" placeholder="請輸入名字">
</div>
</div>
<div class="form-group">
<label for="lastname" class="col-sm-2 control-label">姓</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="lastname" placeholder="請輸入姓">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<div class="checkbox">
<label>
<input type="checkbox">請記住我
</label>
</div>
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="submit" class="btn btn-default">登錄</button>
</div>
</div>
</form>
<!--表單控件狀態-->
<form class="form-horizontal" role="form">
<div class="form-group">
<label class="col-sm-2 control-label">聚焦</label>
<div class="col-sm-10">
<input class="form-control" id="focusedInput" type="text" value="該輸入框獲得焦點...">
</div>
</div>
<div class="form-group">
<label for="disabledInput" class="col-sm-2 control-label">禁用</label>
<div class="col-sm-10">
<!--禁用的輸入框 input-->
<input class="form-control" id="disabledInput" type="text" placeholder="該輸入框禁止輸入..." disabled>
</div>
</div>
<!--禁用的字段集 fieldset-->
<fieldset disabled>
<div class="form-group">
<label for="disabledTextInput" class="col-sm-2 control-label">禁用輸入（Fieldset disabled）</label>
<div class="col-sm-10">
<input type="text" id="disabledTextInput" class="form-control" placeholder="禁止輸入">
</div>
</div>
<div class="form-group">
<label for="disabledSelect" class="col-sm-2 control-label">禁用選擇菜單（Fieldset disabled）</label>
<div class="col-sm-10">
<select id="disabledSelect" class="form-control">
<option>禁止選擇</option>
</select>
</div>
</div>
</fieldset>
<!--驗證狀態-->
<div class="form-group has-success">
<label class="col-sm-2 control-label" for="inputSuccess">輸入成功</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="inputSuccess">
</div>
</div>
<div class="form-group has-warning">
<label class="col-sm-2 control-label" for="inputWarning">輸入警告</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="inputWarning">
</div>
</div>
<div class="form-group has-error">
<label class="col-sm-2 control-label" for="inputError">輸入錯誤</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="inputError">
</div>
</div>
</form>