Flutter readAsBytesSync 文件读取不完整以编码 base64

Question

1. List item

I'm trying to send a JPG image (captured by ImagePicker in emulator) via HTTP POST with base64 encoding to an AWS REST API. But readAsBytesSync() operation only reads a (head) part of the image (I've tested it printing to the string as bytes) thus base64 can only encode that small part. What may be the reason, many thanks for your help in advance.

  Future<void> captureImage(ImageSource imageSource) async {
    try {
      ImagePicker picker = ImagePicker();
      final pickedFile = await picker.getImage(
          source: ImageSource.camera,
          preferredCameraDevice: CameraDevice.front);
                 String theimagepath = pickedFile.path.toString();
        //_imageFile = imageFile;
       
        print('theimagepath just below');
        print(theimagepath);
         
           String img64 = base64Encode(Io.File(theimagepath).readAsBytesSync());
           //print('bytes'+bytes.toString());
         
           print('img64:   '+img64);
 _imageFile = Io.File(pickedFile.path);


      setState(() {
        print('State here is ');

------------- DEBUG OUTPUT BELOW (base64 encoded string is incomplete) -------------

I/flutter (13629): theimagepath just below
I/flutter (13629): /storage/emulated/0/Android/data/com.example.blabla/files/Pictures/f8a0295e-9ce5-446c-91d2-41c938e49b7f5430316734413263510.jpg
I/flutter (13629): img64:   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
I/flutter (13629): State here is

Answer 1

This also happened to me here .

I thought at first it was in front-end(flutter) but upon hours of inspecting and research what happens is that the back-end (go lang) receiver's buffer reader closes it just before the whole base64 was sent through an API call.