Failed to convert parameter C# / SQL Server

Question

Getting error:

Failed to convert parameter value from string to a Int32

I write that code for my form and at finally when run the co

Answer 1

why you don't use

comm.Parameters.AddWithValue("@cod", T4.Text);

comm.Parameters.AddWithValue("@facultate", C1.Text);
comm.Parameters.AddWithValue("@domeniul", T1.Text);
    ... 

comm.Parameters.AddWithValue("@d_inscriere", DTP1.Value);

    ...
    etc