获取存储过程output参数出错!

Question

存储过程代码:CREATE PROCEDURE ShowCount
@Count INT OUTPUT
AS
SELECT @Count=COUNT(*) FROM Orders
GO
C#代码:SqlConnection sqlCon = new SqlConnection("Server=.;Initial Catalog=Northwind;Integrated Security=SSPI");            try
            {
                sqlCon.Open();                SqlCommand sqlCom = new SqlCommand();
                sqlCom.CommandType = CommandType.StoredProcedure;
                sqlCom.CommandText = "ShowCount";
                sqlCom.Connection = sqlCon;
                sqlCom.Parameters.Add(new SqlParameter("@Count", SqlDbType.Int));
                sqlCom.Parameters["@Count"].Direction = ParameterDirection.Output;                toolCount.Text = sqlCom.Parameters["@Count"].Value.ToString();
            }
            catch (Exception ex)
            {
                toolError.Text = ex.Message;
            }
            finally
            {
                sqlCon.Close();
            }
出现错误提示:未将对象引用设置到对象的事例.

Answer 1

SqlConnection sqlCon = new SqlConnection("Server=.;Initial Catalog=Northwind;Integrated Security=SSPI");            try
            {
                sqlCon.Open();                SqlCommand sqlCom = new SqlCommand();
                sqlCom.CommandType = CommandType.StoredProcedure;
                sqlCom.CommandText = "ShowCount";
                sqlCom.Connection = sqlCon;
                sqlCom.Parameters.Add(new SqlParameter("@Count", SqlDbType.Int));
                sqlCom.Parameters["@Count"].Direction = ParameterDirection.Output;
                sqlCom.ExecuteNonQuery();
                toolCount.Text = sqlCom.Parameters["@Count"].Value.ToString();
            }
            catch (Exception ex)
            {
                toolError.Text = ex.Message;
            }
            finally
            {
                sqlCon.Close();
            }