用React上传多张图片

1. 为了纠正错误，

   TypeError: Cannot read property 'files' of null.

   您需要更改

   state

   声明

   state = {
   files: []
   }
   
   

2. 如果您希望有机会选择多个文件，可以使用

   multiple

   选项

或者，如果您想要一张一张地选择图片，则您的实现应该可以正常工作，只需修正

state

e.target.files

    class ImageUpload extends React.Component {      state = {        files: []      }      fileSelectedHandler = (e) => {        this.setState({ files: [...this.state.files, ...e.target.files] })      }      render() {        return (          <form> <div><h2>Upload images</h2></div> <h3>Images</h3> <input type="file" multiple onChange={this.fileSelectedHandler} />          </form>        )      }    }    ReactDOM.render(<ImageUpload />, document.getElementById('app'))    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>    <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>    <div id="app"></div>