:read-only和:read-write是用于根據(jù)元素是否可編輯進(jìn)行樣式的偽類，1.:read-only用于不可編輯元素如帶readonly屬性的輸入框；2.:read-write用于可編輯元素如普通文本框和contenteditable區(qū)域；3.它們適用于表單設(shè)計、動態(tài)界面和條件樣式，但需配合HTML屬性使用以確保功能正確；4.現(xiàn)代瀏覽器支持良好，但I(xiàn)E早期版本可能不兼容。

In CSS, :read-only and :read-write are pseudo-classes that let you style elements based on whether they’re editable or not. They might not be as commonly used as :hover or :focus, but they come in handy when dealing with form inputs and contenteditable elements.

When to Use :read-only

This pseudo-class targets elements that are not editable by the user. That includes input fields with the readonly attribute, or elements like <div> or <code><span></span> that aren’t meant for editing.

For example:

<input type="text" value="I'm read-only" readonly>

You can style it like this:

input:read-only {
  background-color: #f0f0f0;
  border: 1px solid #ccc;
}

It’s useful when you want to visually distinguish non-editable fields from regular ones — maybe to make them look more static or grayed out.

Note: Just because an element is styled with :read-only, it doesn't mean it's actually locked — always use the readonly attribute in HTML for real behavior control.

When to Use :read-write

On the flip side, :read-write applies to elements users can edit. This includes standard text inputs, textareas, and even elements with the contenteditable attribute set.

Here’s a basic example:

<textarea>I'm editable</textarea>
<div contenteditable="true">Edit me too!</div>

And the corresponding CSS:

:read-write {
  border: 2px dashed #4caf50;
}

This selector is especially helpful if you want to apply consistent styles across all editable areas — say, adding a subtle highlight or different padding.

Also, keep in mind that even password fields (<input type="password">) are considered :read-write, so your styles will apply there too unless you specifically exclude them.

Practical Use Cases

Here are a few places where these pseudo-classes can really shine:

• Form design: Highlight editable vs non-editable fields to improve UX.
• Dynamic interfaces: Style contenteditable regions differently to signal interactivity.
• Conditional styling: Combine with other selectors (like :focus or :invalid) to build smarter UI rules.

For example, if you're building a CMS where some fields are locked after approval, using :read-only makes it easy to give visual feedback without extra classes.

Another trick: You can invert the logic and write something like:

input:not(:read-only) {
  /* Styles for editable inputs only */
}

That gives you more precise control without writing extra markup.

Browser Support and Caveats

These pseudo-classes are well-supported in modern browsers including Chrome, Firefox, Safari, and Edge. However, older browsers like Internet Explorer (especially versions before IE12) may not support them fully.

Also, keep in mind:

• :read-only and :read-write don't change behavior, only appearance.
• Always pair visual cues with actual attributes (readonly, disabled, etc.) for accessibility and functionality.

So while they’re not essential for every project, they’re definitely worth having in your CSS toolkit when working with forms or editable content.

基本上就這些。