草案
此页面不完整。
readonly
attribute, when present, makes the element not mutable, meaning the user can not edit the control.
若
readonly
attribute is specified on an input element, because the user can not edit the input, the element does not participate in constraint validation.
readonly
attribute is supported by
text
,
search
,
url
,
tel
,
email
,
password
,
date
,
month
,
week
,
time
,
datetime-local
，和
number
types and the
<input>
form control elements. If present on any of these input types and elements, the
<textarea>
pseudo class will match. If the attribute is not included, the
:read-only
pseudo class will match.
:read-write
The attribute is not supported or relevant to
or input types that are already not mutable, such as
checkbox
and
radio
or cannot, by definition, start with a value, such as the
file
input type.
range
and
color
, as both have default values. It is also not supported on
hidden
as it can not be expected that a user to fill out a form that is hidden. Nor is it supported on any of the button types, including
<select>
image
.
注意：
Only text controls can be made read-only, since for other controls (such as checkboxes and buttons) there is no useful distinction between being read-only and being disabled, so the
readonly
attribute does not apply.
When an input has the
readonly
attribute, the
:read-only
pseudo-class also applies to it. Conversely, inputs that support the
readonly
attribute but don't have the attribute set match the
:read-write
pseudo-class.
差异在
被禁用
and
readonly
is that read-only controls can still function and are still focusable, whereas disabled controls can not receive focus and are not submitted with the form and generally do not function as controls until they are enabled.
Because a read-only field cannot have it's value changed by a user interaction,
required
does not have any effect on inputs with the
readonly
attribute also specified.
The only way to modify dynamically the value of the readonly attribute is through a script.
注意：
required
attribute is not permitted on inputs with the
readonly
attribute specified.
Browsers display the
readonly
attribute...
If the element is readonly, then the element's value can not be updated by the user, and does not participate in constraint validation.
<div class="group"> <input type="textbox" value="Some value" readonly="readonly"/> <label>Textbox</label> </div> <div class="group"> <input type="date" value="2020-01-01" readonly="readonly"/> <label>Date</label> </div> <div class="group"> <input type="email" value="Some value" readonly="readonly"/> <label>Email</label> </div> <div class="group"> <input type="password" value="Some value" readonly="readonly"/> <label>Password</label> </div> <div class="group"> <textarea readonly="readonly">Some value</textarea> <label>Message</label> </div>
<fieldset>
<legend>Checkboxes buttons</legend>
<p><label>
<input type="checkbox" name="chbox" value="regular"> Regular
</label></p>
<p><label>
<input type="checkbox" name="chbox" value="readonly" readonly> readonly
</label></p>
<p><label>
<input type="checkbox" name="chbox" value="disabled" disabled> disabled
</label></p>
</fieldset>
<fieldset>
<legend>Radio buttons</legend>
<p><label>
<input type="radio" name="radio" value="regular"> Regular
</label></p>
<p><label>
<input type="radio" name="radio" value="readonly" readonly> readonly
</label></p>
<p><label>
<input type="radio" name="radio" value="disabled" disabled> disabled
</label></p>
</fieldset>
No compatibility data found. Please contribute data for "html.elements.attributes.readonly" (depth: 1) to the MDN 兼容性数据存储库 .