DateTime.TryParse实现问题

Question

I have this code where I need to determine if the received value is DateTime, if so, return 0 otherwise return the value in order to calculate sum:

row["Total"] = months.Sum(kv =>
                            {
                                DateTime dateValue;
                                if (!DateTime.TryParse(kv.Value, out dateValue))
                                {
                                    return double.Parse(kv.Value);
                                }
                                else
                                {
                                    return 0;
                                }
                            });

but these values are being treated as DateTime as well?

1726.07

4756.06

1.08

1.27

1.11

will every double value be treated as DateTime then?

Answer 1

What if you do it 'all the way around' :

row["Total"] = months.Sum(kv =>
                            {
                                double toReturn = 0;
                                if (!Double.TryParse(kv.Value, out toReturn )) return 0;

                                return toReturn;            
                            });

Sometimes double values can be parsed using DateTime.Parse but i don't believe you can parse date like "22/06/2015" to double. And you don't really need this 'else' statement.

Other option would be to use DateTime.TryParseExact and specify format for your date...

Answer 2

You can try this..

DateTime dateValue;
months.Where(kv=>(!DateTime.TryParse(kv.Value, out dateValue))).Sum(kv =>double.Parse(kv.Value));//Sum of values where values are not datetime