Can't convert from int to "classname" - asp.net-mvc

Question

While building a ASP.NET-MVC website I was trying to implement a EDIT page on my website, but I'm having some difficulties, particulary in my Controller. The error is in this class, pointing to the ID:
public IActionResult Edit(int ID = 0)
{
GestaoAlertas _teste = addresses.Contains(ID);
return View(_teste);
}
And the error says:
It is not possible to convert from int to "hdsportal.GestaoAlertas"
Controller:
public class HomeController : Controller
{
SqlCommand com = new SqlCommand();
SqlDataReader dr;
SqlConnection con = new SqlConnection();
List<GestaoAlertas> addresses = new List<GestaoAlertas>();
private readonly ILogger<HomeController> _logger;
public HomeController(ILogger<HomeController> logger)
{
_logger = logger;
con.ConnectionString = "secret";
}
public IActionResult Gestao_Alertas()
{
FetchData();
return View(addresses);
}
[Route("")]
public IActionResult Index()
{
FetchData();
return View(addresses);
}
public IActionResult Edit(int ID = 0)
{
GestaoAlertas _teste = addresses.Contains(ID);
return View(_teste);
}
public IActionResult Privacidade()
{
return View();
}
public IActionResult Gestao_Utilizadores()
{
return View();
}
public IActionResult Contatos()
{
return View();
}
public IActionResult QuemSomos()
{
return View();
}
private void FetchData()
{
if (addresses.Count > 0)
{
addresses.Clear();
}
try
{
con.Open();
com.Connection = con;
com.CommandText = "SELECT [ID], [SYSTEM_NAME], [SYSTEM_STATUS], [SYSTEM_SHORTMSG] FROM [CORE_SYS_STATUS]";
dr = com.ExecuteReader();
while (dr.Read())
{
addresses.Add(new GestaoAlertas()
{
ID = (int)dr["ID"]
,
SYSTEM_NAME = dr["SYSTEM_NAME"].ToString()
,
SYSTEM_STATUS = dr["SYSTEM_STATUS"].ToString()
,
SYSTEM_SHORTMSG = dr["SYSTEM_SHORTMSG"].ToString()
});
}
con.Close();
}
catch (Exception ex)
{
throw ex;
}
}
[ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
public IActionResult Error()
{
return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
}
}
Model:
public class GestaoAlertas
{
public int ID { get; set; }
public string SYSTEM_NAME { get; set; }
public string SYSTEM_STATUS { get; set; }
public string SYSTEM_SHORTMSG { get; set; }
}

Answer 1

Issue & Concern
According to List<T>.Contains(T), you need parse T object which is GestaoAlertas object to your addresses (List<GestaoAlertas> type).
Hence, you get the error below as it is an unmatched type with int
It is not possible to convert from int to "hdsportal.GestaoAlertas"
for this line:
GestaoAlertas _teste = addresses.Contains(ID);
And List<T>.Contains(T) returns the boolean result.
public bool Contains (T item);
Determines whether an element is in the List.
Solution(s)
Assumptions:
addresses contain GestaoAlertas records
You can get GestaoAlertas element from addresses by ID with either of these LINQ methods:
Pre-requisite:
Import System.Linq namespace.
using System.Linq;
Solution 1: Enumerable.SingleOrDefault
Returns a single, specific element of a sequence, or a default value if that element is not found.
Note: It will throw InvalidOperationException if input sequence contains more than one element. Good to be use for unique identifier such as ID.
GestaoAlertas _teste = addresses.SingleOrDefault(x => x.ID == ID);
Solution 2: Enumerable.Single
Returns a single, specific element of a sequence.
Note: It will throw ArgumentNullException if it returns null.
GestaoAlertas _teste = addresses.Single(x => x.ID == ID);
Solution 3: Enumerable.FirstOrDefault
Returns the first element of a sequence, or a default value if no element is found.
GestaoAlertas _teste = addresses.FirstOrDefault(x => x.ID == ID);
Solution 4: Enumerable.First
Returns the first element of a sequence.
Note: It will throw ArgumentNullException if it returns null.
GestaoAlertas _teste = addresses.First(x => x.ID == ID);