## zh-CN

点击上传用户头像，并使用 `beforeUpload` 限制用户上传的图片格式和大小。

> `beforeUpload` 的返回值可以是一个 Promise 以支持异步处理，如服务端校验等：[示例](https://upload-react-component.vercel.app/demo/before-upload#beforeupload)。

## en-US

Click to upload user's avatar, and validate size and format of picture with `beforeUpload`.

> The return value of function `beforeUpload` can be a Promise to check asynchronously. [demo](https://upload-react-component.vercel.app/demo/before-upload#beforeupload)