在React.js中检查文件输入类型

import React, { Component } from 'react';

class FileInput extends Component {
  constructor(props) {
    super(props);
    this.state = {
      fileType: ''
    };
  }

  handleFileChange = (event) => {
    const file = event.target.files[0];
    const fileType = file.type;

    // 检查文件类型是否为图像
    if (/^image\//.test(fileType)) {
      this.setState({ fileType });
    } else {
      this.setState({ fileType: 'Invalid file type. Please select an image.' });
    }
  }

  render() {
    return (
      <div>
        <input type="file" onChange={this.handleFileChange} />
        <p>Selected file type: {this.state.fileType}</p>
      </div>
    );
  }
}

export default FileInput;