Flutter&Firebase：上传图片前的压缩

File _imageFile;

_getImage() async {
    var filename = await ImagePicker.pickImage();
    setState(() {
        _imageFile = filename;
    });
}

之后,我发送照片与此代码：

final String rand1 = "${new Random().nexTint(10000)}";
final String rand2 = "${new Random().nexTint(10000)}";
final String rand3 = "${new Random().nexTint(10000)}";
final StorageReference ref = FirebaseStorage.instance.ref().child('${rand1}_${rand2}_${rand3}.jpg');
final StorageUploadTask uploadTask = ref.put(_imageFilE);
final Uri downloadUrl = (await uploadTask.futurE).downloadUrl;
print(downloadUrl);

问题是照片通常非常大.在上传之前,Flutter / Dart中是否有任何压缩和调整照片大小的方法？我很好,质量下降.