lỗi khi code C# giúp em với

[anhduong123]

em đang code bài quản lý sinh viên
form của em gồm 3 buttom thêm sưa xóa
thêm và xóa đã ok rồi nhưng khi muốn sửa 1 sinh viên thì nó hiện lỗi sau:
The SqlParameterCollection only accepts non-null SqlParameter type objects.
Parameter name: value
cụ thể
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;


namespace QUANLYSINHVIEN
{
class SinhVienDao
{

SqlConnection bkn = new SqlConnection(@"server=duongk5\sqlexpress;database =QUANLYSINHVIEN;user=sa;password=123456");

public DataTable view_text(string s)
{
bkn.Open();
SqlDataAdapter da = new SqlDataAdapter(s, bkn);
DataTable dt = new DataTable();
da.Fill(dt);
bkn.Close();
return dt;

}
public void proc_TS(string s, SqlParameter[] sp)
{

bkn.Open();
SqlCommand cmd = new SqlCommand(s, bkn);
cmd.CommandType = CommandType.StoredProcedure;
foreach (SqlParameter s1 in sp)
{
cmd.Parameters.Add(s1);// lỗi tại đây
}
cmd.ExecuteNonQuery();

bkn.Close();
}
}
}
pro nào giúp em với

[hanhkhat]

đây là cái DBExcute của mình. Bạn tham khảo nhé

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace DataAccess
{
    public abstract class DBExecute
    {
        public abstract DataTable Execute_Table(string Text, SqlParameter[] para, CommandType cmdType);
        public abstract DataTable Execute_Table1(string Text, SqlParameter[] para, CommandType cmdType);
        public abstract IDataReader Execute_DataReader(string Text, SqlParameter[] para, CommandType cmdType);
        public abstract DataSet Execute_Tables(string Text, SqlParameter[] para, CommandType cmdType);
        public abstract object Execute_Object(string Text, SqlParameter[] para, CommandType cmdType);
        public abstract int Execute_Modify(string Text, SqlParameter[] para, CommandType cmdType);
    }
    public class SQLExecute : DBExecute
    {
        SqlConnection cnn;
        string connectionString;
        public SQLExecute()
        {
            this.connectionString = ConfigurationSettings.AppSettings["SqlConnectionString"];
        }

        public SQLExecute(string SqlConnectionString)
        {
            this.connectionString = SqlConnectionString;
        }
        public override DataTable Execute_Table(string Text, SqlParameter[] para, CommandType cmdType)
        {
            using (cnn = new
            SqlConnection(this.connectionString))
            {
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                DataTable table = new DataTable();
                cnn.Open();
                table.Load(cmd.ExecuteReader());
                return table;
            }
        }

        public override DataTable Execute_Table1(string Text, SqlParameter[] para, CommandType cmdType)
        {
            using (cnn = new
            SqlConnection(this.connectionString))
            {
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                DataTable table = new DataTable();
                cnn.Open();
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(table);
                return table;
            }
        }
        public override IDataReader Execute_DataReader(string Text, SqlParameter[] para, CommandType cmdType)
        {
            try
            {
                cnn = new SqlConnection(this.connectionString);
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                cnn.Open();
                return cmd.ExecuteReader(CommandBehavior.CloseConnection);
            }
            catch
            {
                return null;
            }
            finally
            {

            }
        }
        public override DataSet Execute_Tables(string Text, SqlParameter[] para, CommandType cmdType)
        {
            using (cnn = new
            SqlConnection(this.connectionString))
            {
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                DataSet ds = new DataSet();
                cnn.Open();
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(ds);
                return ds;
            }
        }
        public override int Execute_Modify(string Text, SqlParameter[] para, CommandType cmdType)
        {
            using (cnn = new
            SqlConnection(this.connectionString))
            {
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                cnn.Open();
                return cmd.ExecuteNonQuery();
            }
        }
        public override object Execute_Object(string Text, SqlParameter[] para, CommandType cmdType)
        {
            using (cnn = new
            SqlConnection(this.connectionString))
            {
                SqlCommand cmd = new SqlCommand(Text, cnn);
                cmd.CommandType = cmdType;
                if (para != null)
                    cmd.Parameters.AddRange(para);
                cnn.Open();
                return cmd.ExecuteScalar();
            }
        }
    }
}

[hanhkhat]

có thể là nó khác nhau chỗ add và addrange.
bạn thay
cmd.Parameters.Add(s1);
thành
cmd.Parameters.AddRange(s1);
thử xem nhé