SocketException: OS Error: Connection refused, errno = 111 in flutter using django backend

问题

I m building a flutter app with django rest-framework. The registration api is working fine in Postman but after some successful registration from the flutter app it is showing the above error. The request is been sent on https address.

Removed csrf. Nothing happens.

Request:

var data = {'email':signupemailidcontroller.text,
            'password1':passwordcontroller.text,
            'password2':confirmpasswordcontroller.text,
           };
        //http request here
        await http.post(websitesignupurl,
                        headers: headers,
                        body: json.encode(data))
          .then((onResponse){
            print(onResponse.body);
          }).catchError((onerror){
            print(onerror.toString());
        });

Output in Console:

SocketException: OS Error: Connection refused, errno = 111

I Expect the response of this request to be a Json object containing the user and token.

回答1:

Harnish, need a few more details in-order to debug this error.

1. Are you running the server locally or communicating with a remote server?
2. Are you running the app on the Android Emulator?

Possible Solution:

If you're running the server locally and using the Android emulator, then your server endpoint should be 10.0.2.2:8000 instead of localhost:8000 as AVD uses 10.0.2.2 as an alias to your host loopback interface (i.e) localhost

Note on Futures

I noticed above that the code is using await and then on the same line. This can be confusing, to be clear, await is used to suspend execution until a future completes, and then is a callback function to execute after a future completed. The same could be written as below

void myFunction() async {
    var data = {};
    var response = await http.post(URL, headers:headers, body:data);
    if (response.statusCode == 200) {
        print(reponse.body);
    } else {
       print('A network error occurred');
    }
}

or the non async/await method

void myFunction() {
    var data = {};
    http.post(URL, headers:headers, body:data)
    .then((response) => print(response.body))
    .catchError((error) => print(error));
}

For a more detailed information on Futures in Dart please read https://www.dartlang.org/tutorials/language/futures

回答2:

Try adding <uses-permission android:name="android.permission.INTERNET"/> to your manifest. This solved this issue for me.

来源：https://stackoverflow.com/questions/55785581/socketexception-os-error-connection-refused-errno-111-in-flutter-using-djan