SolvedPrivate

get the first Item in a list linq

Posted on 2014-04-22
8
70 Views
Last Modified: 2016-02-16
I am trying to get the first Item in a list and it keeps throwing an error on .Take(1) how can I get this to select the first column (thedepth) of 2 columns  in a list called gammalist
 int t2 = Convert.ToInt32(total);
                    for (int i = 0; t2 >= 100; i++)
                    {
                        int depthToRemove = Convert.ToInt32(Program.myMainControl.dtoc.gammaList.Where(g => g.theDepth).Take(1));
                        Program.myMainControl.dtoc.gammaList.RemoveAt(0);
                        gammaseries.DataPoints.RemoveAt(0);
                        dtg.Rows[0].Delete();
                        t2 = depthToRemove - t2;
                        
                    }

Open in new window

0
Comment
Question by:r3nder
  • 5
  • 3
8 Comments
 
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 40016122
What is the type of gammaList?
0
 
LVL 6

Author Comment

by:r3nder
ID: 40016132
public struct gammaPlots
        {
            public float thedepth { get; set; }
            public float thegamma { get; set; }
        }
public List<gammaPlots> gammaList = new List<gammaPlots>();
0
 
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 40016144
Your problem is you are passing an IEnumerable<gammaPlots> to Convert.ToInt32. I assume you meant to send the first theDepth value. I think you should be using First instead:

int depthToRemove = Convert.ToInt32(Program.myMainControl.dtoc.gammaList.Where(g => g.theDepth).First().theDepth);

Open in new window

0
 
LVL 6

Author Comment

by:r3nder
ID: 40016166
error on g.thedepth
Cannot convert lambda expression to delegate type 'System.Func<SimplyMWDClientGen2.DTO.DTOClass.gammaPlots,bool>' because some of the return types in the block are not implicitly convertible to the delegate return type      
Connot implicitly convert type float to bool
0
3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

 
LVL 75

Accepted Solution

by:
käµfm³d   👽 earned 500 total points
ID: 40016169
Ah, I didn't notice this before, but your Where clause is incomplete. The thing you pass to Where should yield a boolean result.

e.g.

Where(g => g.theDepth > 3.00)

Open in new window


You need to tweak your Where to accommodate such.
0
 
LVL 6

Author Comment

by:r3nder
ID: 40016277
var depthToRemove = Program.myMainControl.dtoc.gammaList.Where(g => g.thedepth >= 0.00).First().thedepth;
this gives me almost all the depths added together - I just want the first depth - what am I doing wrong - I don't see it
0
 
LVL 6

Author Comment

by:r3nder
ID: 40016285
Wait that is getting the depth - I need to do some math now
0
 
LVL 6

Author Closing Comment

by:r3nder
ID: 40016287
Thanks Kaufmed
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Whether you’re a college noob or a soon-to-be pro, these tips are sure to help you in your journey to becoming a programming ninja and stand out from the crowd.
Computer science students often experience many of the same frustrations when going through their engineering courses. This article presents seven tips I found useful when completing a bachelors and masters degree in computing which I believe may he…
Viewers will learn how to properly install Eclipse with the necessary JDK, and will take a look at an introductory Java program. Download Eclipse installation zip file: Extract files from zip file: Download and install JDK 8: Open Eclipse and …
In this fourth video of the Xpdf series, we discuss and demonstrate the PDFinfo utility, which retrieves the contents of a PDF's Info Dictionary, as well as some other information, including the page count. We show how to isolate the page count in a…

867 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now