Re: Sorting by various fields - C# Discussion Boards

This must be the stupidest post of the day. If you were talking to Alex in another thread, reply on that thread ( he'll get an email ).

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

No he isn't. This is his first post.

Rob, I don't feel like posting it here. You're free to go now.

It is a crappy thing, but it's life -^ Carlo Pallini

I'm sorry, but the lifeform you know as Alex is not real. It turns out that Alex is an avatar in an adult forum, and you've been spending far too much time there because now you can't distinguish between fiction and reality; for instance women aren't all 38DD.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

My blog | My articles | MoXAML PowerToys | Onyx

You so just smashed my whole belief system... Cry | :((

Hi,

What would be the best solution for this?
Suppose I have a list of messages.. each message haves date, from, to, etc.

I would like to allow to sort by any of these fields..

Should I make my own MessageCollection class?
or inherite from List<T> ..or ..?

I guess there are a lot of solutions but I would like to know which one is the most used for this problem (which I'm sure it must be a common problem)

Sorry bad english

Make a message class and create function objects to use with the Sort method on List<T> to sort the different ways

Quake2Player wrote:
Sorry bad english

Actually, Englsih was fine, and either way, bad English is one thing no-one should ever punish you for, on an international forum.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

There are, as you say, many solutions to this. As always it comes down to making the right tradeoffs (between encapsulation, performance, coding effort, ...) and there is really no single answer that is "the best way" for all scenarios.

As long as the field types are IComparable you could implement a "ListSorter" class that could sort any List<T> by any field using reflection. This would require relatively little code and the great benefit is that you do it once and then sort whatever object types you want to. The downside is that it's slow, but that may not be a problem if the collections are small. An interesting possibility is to build on this approach by making a ListSorterFactory class instead; this could use reflection to dynamically generate a ListSorter class for a specific type. It may sound like a very advanced sort of thing, but .NET has actually made this kind of thing relatively easy to do.

If you have just one type of collection (and don't mind that this code won't be reusable anytime in the future - a sorter factory is potentially useful in many projects down the line) you can always go for inheriting from List<T> and add sort methods using the built-in Sort function with a predicate that compares the particular field the method sorts by. Since this requires the least code, I'll provide an example, but personally I think the ListSorterFactory is a rather more interesting idea!

public class Item
{
  public int Number;
  public DateTime Time;
  public string Message;
}

public class ItemCollection : List<Item>
{
    public void SortByNumber()
    {
        Sort((Item a, Item b) => a.Number.CompareTo(b.Number));  
    }

    public void SortByTime()
    {
        Sort((Item a, Item b) => a.Time.CompareTo(b.Time));
    }

    public void SortByMessage()
    {
        Sort((Item a, Item b) => a.Message.CompareTo(b.Message));
    }
}

However, since the pattern of this code is so regular, why not just generate it instead of writing it manually? Using reflection you can easily find all public fields or properties (or non-public if that's of interest, though you shouldn't do this with private members in any case!) and generating the code is then completely straightforward.

And now I realize that dynamically compiling such generated code may not be so meaningful, because you've got no obvious way to *use* that generated code in your non-generated code! (If there was a single interface with many implementations generated code would do the trick, but here the generated ListSorter<T> has an interface that itself depends on T.)

Hope this helps. Wink | ;)

I have this problem that i want to generate a mobile agent from sms .. I used GSM modem and C# for coding and use the API ActiveX also.. i finished the mobile agent code and its work properly, but my attempt to bind the agent with the sms faild i dont know what to do ?? can someone help me ?

using System;
using System.Data;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.ComponentModel;
using VDSDKLib;

namespace PSWD_Server
{
    /// <summary>
    /// Summary description for PSWD_WebService
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    
    public class PSWD_WebService : WebService
    {        
        [WebMethod]
        public string HelloWorld()
        {
            return "Hello World";
        }
        [WebMethod]
        public string Help()
        {
            return "Help";
        }
    }
}

After adding this webservice as Web Refrence in the win application

// Windows Application

PSWD_WebService WebSer = new PSWD_WebService();
TextBox1.Text = WebSer.HelloWorld();  // HelloWorld() here acceped and returns good.
TextBox1.Text = WebSer.Help();        // Help() here is not acceped and not readed
private void UnmountDisk()
{
   CreateBtn.Enabled = true;
   DestroyBtn.Enabled = false;
}

so how can make Help() in accepted..
and how can i call UnmountDisk() from the web service..

thanks Smile | :)

Mtyb wrote:
http://tempuri.org/

You must always change this. That's why it says 'temp' This will not fix your issue, tho.

Did you ever have a version that contained the hello world method and not the help method ? Have you tried deleting and recreating the reference ? Have you considered telling us what you mean by 'not accepted and not readed' ? Does it compile ? Does it not run ?

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Now its working good..Thanks!

How can i call a method in windows app from WebService..?

Mtyb wrote:

How can i call a method in windows app from WebService..?

There is absolutely no way to do that. The closest you could get, is to make a webservice call regularly to ask the webservice if it wants to prompt you to do something.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Ok..can u tell me how to connect WebApp with WinApp..sends paramters or call method in WinApp..????

Thanks Smile | :)

I expect you'd write an app on your server, and your client would connect to the server with TCP/IP to announce itself, and then the server could send back messages. Expect lots of grief from firewalls and anti spyware.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

It seems to me that Visual studio 2010 beta 1 is completely free?

is it right?

if so, then what is difference between Visual studio 2010 beta 1 and final version?

only some bugs or sth else?

thanks

Seraph_summer wrote:
It seems to me that Visual studio 2010 beta 1 is completely free?

is it right?

if so, then what is difference between Visual studio 2010 beta 1 and final version?

only some bugs or sth else?

This is C# Forum. It would be better if you ask the Question on Visual Studio Forum[^] or at Loungh[^]

cheers,
Abhijit
CodeProject MVP
Web Site:abhijitjana.net
View My Recent Article

Apart from bugs, it will have a cut off date, after which it will stop working.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Christian Graus wrote:
Apart from bugs

Is that in the release version or the Beta? Wink | ;)

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Yes, I was going to say, the big difference with release will be more bugs, but no time limits.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

I am wondering how MS can let it stop working?

I mean if I download and install it, how MS control it? from internet? or from what?

or there is one pre-set date set in the software?

Probably the same system date based timebomb they use in OS beta/release candidates.

It is a truth universally acknowledged that a zombie in possession of brains must be in want of more brains.
-- Pride and Prejudice and Zombies

i have some ink data. i get the bezier point and bezier cusp of the same. wud bezier cups be considered as the control poits of the curve and is it possible to drwa the exact curve from bezier cusps alone if i discard the bezier points. i searched google but cud not find the satisfactory answer.

Are you sure you have the correct terminology? A cusp is a particular kind of point in a Bezier curve (where the derivative is non-continuous) and only appears in some curves, often when the points are in the wrong order.

If you do have a cusp, it may be possible to calculate the relevant point coordinates, but I suspect you'd need the derivatives on each side of it (and possibly second derivatives) as well. The maths for working this out could be quite complicated...

There are three kinds of people in the world - those who can count and those who can't...

thank you for the reply. further, i do have the coordinates of the cusps. and want to draw curve out of these. i.e using minimum number of points. my requirement is to redraw(approximate) a curve from a given curve and its coordinates with minimum number of points with minimal error.