React如何處理焦點管理和可訪問性？

React本身不直接管理焦點或可訪問性，但提供了有效處理這些問題的工具。 1. 使用Refs來編程管理焦點，如通過useRef設置元素焦點；2. 利用ARIA屬性提升可訪問性，如定義tab組件的結構與狀態；3. 關注鍵盤導航，確保模態框等組件內的焦點邏輯清晰；4. 盡量使用原生HTML元素以減少自定義實現的工作量和錯誤風險；5. React通過控制DOM和添加ARIA屬性輔助可訪問性實現，但正確使用仍依賴開發者。

React itself doesn't directly manage focus or accessibility — that's more the job of the browser and developers. But React gives you tools to handle these things effectively, especially when building complex UIs like dropdowns, modals, or custom controls.

Here's how it works in practice:

Use Refs to Manage Focus Programmatically

If you want to set focus on an element — say, after a modal opens or an error occurs — you'll typically use a ref .

 const inputRef = useRef(null);

useEffect(() => {
  inputRef.current.focus();
}, []);

This is common for form fields, alerts, or dynamically added elements. Just be careful not to overdo it — unexpected focus changes can confuse screen reader users.

ARIA Attributes Improve Accessibility

React supports all standard ARIA attributes, so you can make custom components accessible. For example, if you're building a tab component from scratch:

• Use role="tablist" , role="tab" , and role="tabpanel" to define structure.
• Add aria-selected , aria-controls , and aria-labelledby to manage state and relationships.

These help screen readers understand your UI even when it's not built with native HTML elements like <select></select> or <details></details> .

Keyboard Navigation Is Critical

Focus management isn't just about setting focus — it's also about where focus goes next.

For example, when a modal opens:

• Move focus inside the modal (eg, to the close button or first input).
• Trap focus so it doesn't escape to the background content.
• Restore focus to the triggering element when the modal closes.

You can do this manually using tabIndex , onKeyDown , and refs — or use libraries like react-aria or Reach UI which handle this for you.

Don't Forget Native Elements

Whenever possible, use native HTML elements like <button></button> , <input> , or <a></a> . They come with built-in keyboard and screen reader support. If you build a fake button with a <div> , you'll need to add:<ul> <li> <code>role="button"

That's extra work — and easy to get wrong.

So yes, React helps with accessibility by letting you control the DOM and add ARIA attributes easily, but it's still up to you to use them correctly.
基本上就這些。