如何挑选文件和图像以通过Flutter Web上传

我尝试下面的代码，它的工作。

第一

import 'dart:html';

// variable to hold image to be displayed      Uint8List uploadedImage;//method to load image and update `uploadedImage`    _startFilePicker() async {    InputElement uploadInput = FileUploadInputElement();    uploadInput.click();    uploadInput.onChange.listen((e) {      // read file content as dataURL      final files = uploadInput.files;      if (files.length == 1) {        final file = files[0];        FileReader reader =  FileReader();        reader.onLoadEnd.listen((e) {         setState(() {uploadedImage = reader.result;         });        });        reader.onError.listen((fileEvent) {          setState(() { option1Text = "Some Error occured while reading the file";          });        });        reader.readAsArrayBuffer(file);      }    });    }

现在只是任何小部件，例如按钮，然后调用方法

_startFilePicker()