SolvedPrivate

get the first Item in a list linq

Posted on 2014-04-22
8
73 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
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 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
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
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
 
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

How our DevOps Teams Maximize Uptime

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

Question has a verified solution.

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

Suggested Solutions

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Although it can be difficult to imagine, someday your child will have a career of his or her own. He or she will likely start a family, buy a home and start having their own children. So, while being a kid is still extremely important, it’s also …
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 fifth video of the Xpdf series, we discuss and demonstrate the PDFdetach utility, which is able to list and, more importantly, extract attachments that are embedded in PDF files. It does this via a command line interface, making it suitable …

756 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