CODEWITHSUNDEEP
c#linqlistdatecount
JazzMaster
JazzMaster

Reputation: 717

Counting in a List of objects with Linq, between 2 dates

I'm trying to count objects in a list. My code looks like this:

var count = tempMessages
                 .Where(MessageDate => MessageDate > DateTime.Now.AddSeconds(-6))
                 .Count();

As you can see, I'm trying to count Messages where the MessageDate is max 6 seconds old. But I am getting this error message :

Operator '>' cannot be applied to operands of type 'ChatProj.Models.Message' and 'System.DateTime'

Upvotes: 2

Views: 968

Answers (2)

VahiD
VahiD

Reputation: 1064

Because tempMessages is a list of type 'ChatProj.Models.Message and not DateTime, possibly there is a Date Property on Message so you can write this code:

var count = tempMessages.Where(Message => Message.Date > DateTime.Now.AddSeconds(-6)).Count();

Upvotes: 2

Adam Houldsworth
Adam Houldsworth

Reputation: 64487

tempMessages is an enumerable of a custom class Message, the Where class will take that as the parameter to the expression, so you need to access the date property within it:

There is also an overload on Count that can take an expression to save doing the Where: http://msdn.microsoft.com/en-us/library/bb535181.aspx

var checkDate = DateTime.Now.AddSeconds(-6);

var count = tempMessages
    .Count(message => message.Date > checkDate);

The error message highlights this, you are trying to say "is my message greater than this date", instead of "is the date of this message greater than this date".

Upvotes: 3

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