ExecuteNonQuery requires an open and available Connection.

Question

The connection's current state is closed代码的方法如下：
 public static int ExecuteNonQuery(string connectionString, string cmdText)
        {
            SqlConnection conn = new SqlConnection(connectionString);
            conn.Open();
            int val = 0;
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = cmdText;
            try
            {
                val = cmd.ExecuteNonQuery();
            }
            catch
            {
                conn.Close();
                return val;
            }
            conn.Close();
            return val;
            
        }连接不是打开了，怎么会报这个错误呢？

Answer 1

conn.Close();
  return val;换个位置

Answer 2

 public static int ExecuteNonQuery(string connectionString, string cmdText)
  {
  SqlConnection conn = new SqlConnection(connectionString);
  conn.Open();
  int val = 0;
  SqlCommand cmd = conn.CreateCommand();
  cmd.CommandText = cmdText;
  try
  {
  val = cmd.ExecuteNonQuery();
  }
  catch
  {
  conn.Close();
  return val;
  }
 
     return val;
     conn.Close();
  }

Answer 3

public static int ExecuteNonQuery(string connectionString, string cmdText)
        {
            SqlConnection conn = new SqlConnection(connectionString);
            conn.Open();
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = cmdText;
            try
            {
                return cmd.ExecuteNonQuery() > 0 ? 1 : 0;
            }
            catch
            {
                return 0;
            }
            finally
            {
                conn.Close();
            }        }