c# - 处理来自另一个函数的异常

Question

我想生成一个打开 SQL 连接的方法:

public SqlConnection openConnection (string connString)
{
    using (SqlConnection conn = new SqlConnection(connString))
    {
        try
        {
            conn.Open();
        }
        catch (Exception)
        {
           OrdersFaultException connEx = new OrdersDBInternalFaultException();
           throw new FaultException<OrdersFaultException>(connEx);
           return null;
        }
        return conn;
    }
}

我想知道上面的代码是否正确？或者我应该在 openConnection 中抛出异常并在调用 openConnection 的函数中处理异常？

Answer 1

你不能在这里使用using:没有人想要一个disposed连接。所以您可以模拟使用:

public SqlConnection openConnection (string connString) {
  SqlConnection conn = null;

  try {
    conn = new SqlConnection(connString));

    return conn;
  }
  catch (Exception e) { // <- Probably, you should catch more specific exception, e.g. DataException
    // This "if" (that's a part of typical using emulation scheme) is redundant
    // you may safely remove it unless there's no addition code in the "try"
    // see Todd Bowles comments
    if (!Object.ReferenceEquals(null, conn))
      conn.Dispose();

    // Do not forget to pass the reason (intitial exception e)
    // when throwing your own one
    throw new OrdersDBInternalFaultException(e);    
  }
}