flutter 多文件上传

1、从手机相机选择器获取图片

resultList =await MultiImagePicker.pickImages(

// 选择图片的最大数量

  maxImages:_medicalImageMaxLength -_medicalImages.length,

  // 是否支持拍照

  enableCamera:true,

  materialOptions:MaterialOptions(

// 显示所有照片，值为 false 时显示相册

      startInAllView:true,

      allViewTitle:'所有照片',

      actionBarColor:'#2196F3',

      textOnNothingSelected:'没有选择照片'

  ),

);

2、提交到服务器

ByteData data =await image.getByteData();

final buffer = data.buffer;

FormData form =FormData.fromMap({

  'name': image.name,

  'file':MultipartFile.fromBytes(buffer.asUint8List(data.offsetInBytes, data.lengthInBytes)),

});

await Dio().post(r.host, data: form);

3、重点：ByteData转File

final filename = 'test.jpg';
var bytes = await rootBundle.load("assets/test.jpg");
String dir = (await getTemporaryDirectory()).path;
File file = writeToFile(bytes,'$dir/$filename');

Future writeToFile(ByteData data, String path) {
  final buffer = data.buffer;
  return new File(path).writeAsBytes(
      buffer.asUint8List(data.offsetInBytes, data.lengthInBytes));
}