Flutter 通过Ffltter应用程序与Docker服务器进行交互以进行身份验证

我已经在Docker上创建了一个服务器，并且我能够从postman 执行查询，例如，在本地主机:8000/api/sign-in/上发布包含以下内容的正文:

{
       "email": "john.doe1@example.com",
       "password": "tfX7WgBpkSCu"
}

我怎样才能把这个查询复制到Flutter 应用上呢？ 目前，我try 了以下代码，但不起作用:

final email = emailController.text.trim();
final password = passwordController.text.trim();

const apiUrl = 'http://localhost:8000/api/sign-in/';

try {
  final response = await http.post(
    Uri.parse(apiUrl),
    headers: {'Content-Type': 'application/json'},
    body: jsonEncode({
      'email': email,
      'password': password,
    }),
  );

  if (response.statusCode == 200) {
    // Successful login
    final Map<String, dynamic> data = jsonDecode(response.body);
    final user = data['user'];
    final token = data['token'];

    // Now you can use the 'user' and 'token' as needed
    print('Logged in user: $user');
    print('Token: $token');

    // Navigate to the next screen or perform other actions
  } else {
    // Failed login
    print('Failed to login. Status code: ${response.statusCode}');
    print('Response body: ${response.body}');

    // Handle the error, show a message, etc.
  }
} catch (e) {
  // Handle any exceptions
  print('Error during login: $e');
}

我得到的错误是:

套接字异常:操作系统错误:连接被拒绝，错误号=111

谢谢