How to send a png file by 'application/octet-stream' in Dart/Flutter to Microsoft Custom Vision? - flutter

Question

I know this question could be redundant, but I am trying to send a png file through a POST request to Microsoft Custom Vision in Flutter.
This is my code:
void _makeRequest (File file) async {
String url = "<url>";
Map<String, String> headers = {
"Content-Type": "application/octet-stream",
"Prediction-Key": "<key>",
};
var bytes = file.readAsBytesSync();
var response = await http.post(
url,
headers: headers,
body: bytes,
);
print(response.body);
print(response.statusCode);
}
And when I run this code I get this response:
{"code":"ErrorUnknown","message":"The request entity's media type 'appliction/octet-stream' is not supported for this resource."}

Answer 1

Based on your comment , I think you used the wrong endpoint/URL. Since you're sending image, you have to use the other prediction endpoint that looks like this:
"https://southcentralus.api.cognitive.microsoft.com/customvision/v3.0/Prediction/<Project ID>/classify/iterations/<Iteration number>/image
^ Note ../image
If still can't, please try below code snipper(works for me):
final bytes = file.readAsBytesSync();
var uri = Uri.parse(
"<Prediction endpoint>");
var request = new http.Request("POST", uri)
..headers['Prediction-Key'] = "<Prediction Key>"
..headers['Content-Type'] = "application/octet-stream"
..bodyBytes = bytes;
http.Response response = await http.Response.fromStream(await request.send());
print(request);
print("Result: ${response.statusCode}");
print(response.statusCode);
print(response.body);