How to add value from checkedlistbox into database using stored procedure c# windows forms?

Question

I'm trying to add checked values from checkedlistbox using stored procedure and C#

 public static void CreateDrugsListBox(CheckedListBox DrugsList) 
   {
       try
       {
           SqlConnection con = new SqlConnection(@"connection");
           SqlCommand cmd = new SqlCommand("InsertData_DrugsListBox", con);
           cmd.CommandType = CommandType.StoredProcedure;

           con.Open();
           foreach (string  itemchecked in DrugsList.CheckedItems) 
           {
               cmd.Parameters.Clear();           
               cmd.Parameters.AddWithValue("@DrugsValue", itemchecked); 
               cmd.ExecuteNonQuery();

           }
           con.Close();
      }

       catch (Exception ex)
       {

           MessageBox.Show("Error"+ex, "Error", MessageBoxButtons.OKCancel, MessageBoxIcon.Error);

       }

   }

it displays an error like:

errorSystem.invalidcastException: imposible to make a cast of an object type System.Data.DataRowView in type System.String

Answer 1

private void insert_Click(object sender, EventArgs e)
        {
           insert(list1);

        }
    private void insert(CheckedListBox list1)
     {
    using (SqlConnection conn = new SqlConnection())
      {
      try
      {
     conn.ConnectionString = "data source=servername;User ID=user_name;Password=password;initial catalog=database_name;integrated security=False;MultipleActiveResultSets=True;App=EntityFramework";
    conn.Open();

    SqlCommand cmd = new SqlCommand("InsertData_CityListBox", conn);
     cmd.CommandType = CommandType.StoredProcedure;
      for (int i = 0; i < list1.Items.Count; i++)
      {
       if (list1.GetItemChecked(i))
       {
   string str = (string)list1.Items[i]; //Or try  list1.Items[i].ToString();
        cmd.Parameters.Clear();
        cmd.Parameters.AddWithValue("@city_code", str);
        cmd.ExecuteNonQuery();
      }
    }
            conn.Close();
         }
      catch(Exception e1)
        {

           }

      }
    }

Stored procedure

create PROCEDURE [dbo].[InsertData_CityListBox] 
(@city_code varchar(50) ) 
AS BEGIN 

insert into city(city_code) values (@city_code)
 END;

Form Screen

Table after data insert