Question

Hello i am just Studying 3-tier Application. I am now having a problem with this simple login form.
I always come up with this Error:

Entities.Entities is a type but is not
like used like a variable.

Always Shows: USer ID is incorrect.

public int SearchEntry(UsersEntity UserEntity)
{
  SqlConnection con = new SqlConnection(); 
  con.ConnectionString = connStr;

  try
  {
    SqlCommand cmd = new SqlCommand("sp_SelectUser", con);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.Add("@User", SqlDbType.VarChar, 50).Value = UserEntity.UserName;
    cmd.Parameters.Add("@Pass", SqlDbType.VarChar, 50).Value = UserEntity.Password ;

    SqlParameter p1 = new SqlParameter("ret", SqlDbType.Int);
    p1.Direction = ParameterDirection.ReturnValue;
    cmd.Parameters.Add(p1); 

    con.Open();
    cmd.ExecuteNonQuery();
    Convert.ToInt32(cmd.Parameters["ret"].Value);

    int s = cmd.ExecuteNonQuery();
    cmd.Dispose();

    return s;
  }
  catch (SqlException)
  {
     throw;
  }
  finally
  {
    con.Close();
    con.Dispose();                  
  }

------------------------------------------------------------------------------------------
 public class BLL
 {
   public int SearchEntry(UsersEntity UserEnity)
   {
     DAL pDAL = new DAL();

     int i = pDAL.SearchEntry(UserEnity);
     return i;               
   }    
}

-------------------------------------------------------------------------------------------
PRESENTATION LAYER:

private void btnLogin_Click(object sender, EventArgs e)
{
  BLL aBl = new BLL();

  UsersEntity uEt = new UsersEntity();             
  uEt.UserName = txtUser.Text;
  uEt.Password = txtPass.Text;

  int r = ****(int)aBl.SearchEntry(uEt.UserName,uEt.Password);****
  if (r == -1)
  {
    MessageBox.Show("Incorrect User Id");
  }
  else if (r == -2)
  {
    MessageBox.Show("Incorrect Password");
  }
  else if (r == 1)
  {
    MessageBox.Show("Welcome");    
  }
  else
  {
    MessageBox.Show("Incorrect User Id / Password ");
  }                   
}

Stored Procedure Code

ALTER PROCEDURE [dbo].[sp_SelectUser] 
-- Add the parameters for the stored procedure here
        @User VARCHAR(50),
        @Pass VARCHAR(50)
AS
        DECLARE @Ap AS VARCHAR(50)

        -- SET NOCOUNT ON added to prevent extra result sets from
        -- interfering with SELECT statements.
        -- Insert statements for procedure here
        SELECT @Ap = @Pass
        FROM   InventoryManager.dbo.Users
        WHERE  UserName = @User

        IF @Ap    IS NULL
        RETURN -1
        ELSE
        IF @Ap=@Pass
        RETURN 1
        ELSE
        RETURN -2

Answer 1

The error you are receiving is because SearchEntry() needs a UsersEntity as a parameter but you are calling it with two strings.

Try replacing:

int r = ****(int)aBl.SearchEntry(uEt.UserName,uEt.Password);****

with:

int r = (int)aBl.SearchEntry(uEt);

That being said, there may be more errors in your code.