我试图访问一个简单的控制台应用程序中的存储过程,出于某种原因,我得到一个InvalidCastException
。存储过程InvalidCastException错误
任何人都可以帮忙吗?
class Customer
{
public int CustomerID { get; set; }
public string FirstName { get; set; }
public string SecondName { get; set; }
public int Age { get; set; }
}
static void Main(string[] args)
{
string storedProc = "dogssimple";
List<Customer> custList = new List<Customer>();
SqlConnection conn = new SqlConnection("server=localhost;" +
"Trusted_Connection=yes;" +
"database=mydatabase; " +
"connection timeout=30");
try
{
conn.Open();
SqlCommand cmd = new SqlCommand(storedProc, conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataReader rdr = cmd.ExecuteReader();
while (rdr.Read())
{
Customer addCustomer = new Customer() //..... cast exception here
{
CustomerID = (int)rdr["CustomerID"],
FirstName = (string)rdr["FirstName"],
SecondName = (string)rdr["SecondName"],
Age = (int)rdr["Age"],
}; //....
Console.WriteLine("Customer: {0}, {1}, {2}, {3}", addCustomer.CustomerID, addCustomer.FirstName, addCustomer.Age, addCustomer.Age);
custList.Add(addCustomer);
}
var age = from x in custList
select x.Age;
var avgAge = age.Average();
Console.WriteLine("The average age of the customers is " + avgAge);
}
catch (Exception e)
{
Console.WriteLine(e); ;
}
Console.ReadLine();
}
包含整个堆栈跟踪。快速猜测会从存储过程返回的类型与您正在投射的内容不匹配。 – AlG 2014-11-14 17:52:08