如何使用自定义按钮在reactjs中读取和上传文件

import React from 'react';

class FileUploader extends React.Component {
  constructor(props) {
    super(props);
    this.fileInput = React.createRef();
  }

  handleFileUpload = () => {
    const file = this.fileInput.current.files[0];
    // 处理文件上传逻辑，可以使用fetch或axios发送文件到服务器
    // 例如：fetch('/upload', { method: 'POST', body: file });
  }

  render() {
    return (
      <div>
        <input type="file" ref={this.fileInput} />
        <button onClick={this.handleFileUpload}>上传文件</button>
      </div>
    );
  }
}

export default FileUploader;

import React from 'react';
import FileUploader from './FileUploader';

class App extends React.Component {
  render() {
    return (
      <div>
        <h1>文件上传示例</h1>
        <FileUploader />
      </div>
    );
  }
}

export default App;