收到错误消息：CS0029：无法隐式转换（ASP.NET Core MVC 和 C#）

Question

I'm getting that error message while trying to define my controller functions (I'm using ASP.NET Core 5.0). I've been trying to solve it for a while but without success, I'm pretty much stuck.

Take a look:

Controller functions showing error:

public ActionResult Edit(int id)
{
    using (Approver approver = dbContext.GetApproverbyId(id))
    {
        return View(approver);
    }
}

public ActionResult Index()
{
    List<approver> approverList = dbContext.GetAllapprovers().ToList();
    return View(approverList);
}

public ActionResult Details(int id)
{
    approver approver = dbContext.GetApproverbyId(id);
    return View(approver);
}

My CONTEXT functions:

public IEnumerable<approver> GetAllapprovers()
{
    var approverList = new List<approver>();

    using (SqlConnection con = new SqlConnection(connectionString))
    {
        SqlCommand cmd = new SqlCommand("SP_GetAllApprovers", con)
                {
                    CommandType = System.Data.CommandType.StoredProcedure
                };

        con.Open();

        SqlDataReader dr = cmd.ExecuteReader();

        while (dr.Read())
        {
            var approver = new approver
                    {
                        CODE = Convert.ToInt32(dr["CODE"].ToString()),
                        MAIL = dr["MAIL"].ToString()
                    };

            approversList.Add(approver);
        }

        con.Close();
    }

    return approversList;
}

public approver GetApproverbyId(int? id)
{
    var approver = new approver();

    using (SqlConnection con = new SqlConnection(connectionString))
    {
        SqlCommand cmd = new SqlCommand("SP_GetapproverById", con);
        cmd.CommandType = System.Data.CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@CODE", id);

        con.Open();

        SqlDataReader dr = cmd.ExecuteReader();

        while (dr.Read())
        {
            approver.CODE = Convert.ToInt32(dr["CODE"].ToString());
            approver.MAIL = dr["MAIL"].ToString();
        }

        con.Close();
    }

    return approver;
}

What am I doing wrong? Can help me to solve this?. I'm pretty lost

Lines showing error:

dbContext.GetApproverbyId(id))

dbContext.GetAllapprovers().ToList();

dbContext.GetApproverbyId(id);

---

---

Answer 1

I think the problem made by your "connectionstring".SQL connection failed to pick your "appsettings.json's"file's connetionstring. for that you found error here

dbContext.GetApproverbyId(id))

dbContext.GetAllapprovers().ToList();

dbContext.GetApproverbyId(id); So you have to pick your connectionstring correctly.

private IConfiguration Configuration;
public HomeController(IConfiguration _configuration)
    {
        Configuration = _configuration;
    }

Now you have to some changes your context function

public IEnumerable<approver> GetAllapprovers()
{
    var approveresLista = new List<approver>();
    string connectionString=  Configuration.GetConnectionString("YOUR CONNECTION STRING NAME");

    using (SqlConnection con = new SqlConnection(connectionString))
    {
        SqlCommand cmd = new SqlCommand("SP_GetAllApprovers", con)
                {
                    CommandType = System.Data.CommandType.StoredProcedure
                };

        con.Open();

        SqlDataReader dr = cmd.ExecuteReader();

        while (dr.Read())
        {
            var approver = new approver
                    {
                        CODE = Convert.ToInt32(dr["CODE"].ToString()),
                        MAIL = dr["MAIL"].ToString()
                    };

            approversList.Add(approver);
        }

        con.Close();
    }

    return approversList;
}

Use your other context methods same as above. I think it will work.if you have any issues with the above code. let me know.