回答-BFW问答

可以使用get方式
import 'package:http/http.dart' as http;
import 'dart:async';

final Map _login={
"username":null,
"password":null
};

//manually add parameters to the URL
final loginData = await http.post(
"http://www.xxxx.com/dev/api/user/userLogin.php?username="+_login["username"]+"&password="+_login["password"], // change with your API
body: paramDic,
);

print(loginData.body);