Codepolice.net » C#

Create a comma separated list with LINQ in C#

Ola — Tue, 20 Apr 2010 13:29:59 +0000

For some reason I always forget that you do not do .Join on your actual string array. So i might as well write it down here so i never forget about this again.

string mycommalist = string.Join(",", alternatives.Select(x=>x.Item.Name).ToArray())

Convert String Array to Int Array and vice versa in C#

Ola — Sat, 07 Nov 2009 15:35:17 +0000

Sometimes you want to convert arrays back and forth. This is to nice extension methods to convert a int array into a string array and vice versa.

public static class ExtensionMethods {

  public static string[] ToStringArray(this int[] intArray) {
   return Array.ConvertAll(intArray, delegate(int intParameter) { return intParameter.ToString(); });
  }

  public static int[] ToIntArray(this string[] strArray) {
   return Array.ConvertAll(strArray, delegate(string intParameter) { return int.Parse(intParameter.ToString()); });
  }
}

file_get_contents() in asp.net/C#

Ola — Fri, 13 Feb 2009 11:25:59 +0000

The URL shortening service http://bit.ly has a really simple and convient API that lets just get a short url like this.

http://bit.ly/api?url=http://www.myreallylong.com/url/with/lots?of=crap

I’ve used this in a wordpress installation with PHP before and there i could just do.

$twitter_url .= file_get_contents('http://bit.ly/api?url=' . get_permalink());

Simple and clean. But today i wanted to do the same thing with asp.net and found myself kind of lost. At last i came up with this, not as simple solution. But it works.

string shortUrl = new StreamReader(WebRequest.Create("http://bit.ly/api?url=http://fragor.ohsohightech.se" + Url.Action("Question", new { number = question.Number, title = question.Title.ConvertTextToUrl() })).GetResponse().GetResponseStream()).ReadToEnd();

Group By with LINQ

Ola — Mon, 24 Nov 2008 12:16:58 +0000

Today i wanted to do a group by query with LINQ wich is something i never done before. I turned out to be kind of easy.

If you just want to group by a single field.

(from s in db.CrewStatsSet
where s.LogDate >= date1 && s.LogDate <= date2 && s.Action == action
group s by s.User.nick into g
orderby g.Count() descending
select new CrewStatsData
{
Nick = g.Key,
Count = g.Count(),
}).ToList();

And if you need to group by multiple fields.

(from s in db.CrewStatsSet
where s.LogDate >= date1 && s.LogDate <= date2 && s.Action == action
group s by new { s.User.nick, s.Action, s.User.userID } into g
orderby g.Count() descending
select new CrewStatsData
{
Nick = g.Key.nick,
Count = g.Count(),
ActionId = g.Key.Action,
UserId = g.Key.userID
}).ToList();

Create a tag cloud with limited amout of tags in ASP.NET and LINQ

Ola — Tue, 14 Oct 2008 15:13:12 +0000

Today i built a Tag cloud for my new site. I found this great article about on how to do it with LINQ and C#. But i missed some features. Especially how to limit the number of tags that was shown. So if you read that article and then have a look at this code if you have the same problem as me.

var tagSummary = (from ti in db.TagItemRelations
group ti by ti.Tag.Text into tagGroup
select new {
Tag = tagGroup.Key,
TagFrequency = tagGroup.Count()
}).OrderByDescending(x=>x.TagFrequency).Take(20);

int maxTagFrequency = (from t in tagSummary select t.TagFrequency).Max();

var tagCloud = (from ti in tagSummary
select new TagCloudItem {
Tag = ti.Tag,
Weight = (double)ti.TagFrequency / maxTagFrequency * 100
}).OrderBy(x=>x.Tag);

The main difference between my code and the code in the article is that i have slightly more complex data model (should not matter) and that i make the second query against the “result” from the first query. This allow me to first order by popularity and then in alphabetic order.

Please leave a comment if there is any better way to do this or if you have any questions.

Using JQuery Validation plugin with ASP.NET

Ola — Thu, 09 Oct 2008 13:42:53 +0000

Like everyone else i’ve been playing around with JQuery alot latley. Asp.net and JQuery is not the best friends in the world but i guess it will be alot better when using ASP.NET MVC. Microsoft also annoncued that they will support JQuery natively in future versions. Nice!

If you want to learn more about ASP.NET and Jquery be sure to read both Rick Sthral’s and the Encosia blogs.

I’m working on a new project now where i am trying to stay away from asp.net ajax mainly because of performance reasons but also just because i want to learn something new. Today i’ve been using the JQuery Validation plugin.

There is alot of documentation of how to use it on the the documentation pages for the plugin but i want to share with you one thing that i had problems with.

This is some regular example code that all the sample’s use. The problem here is that for example “EmailTextbox” is not the ID of the control but the name.

$(document).ready(function() {
// validate signup form on keyup and submit
$("#aspnetForm").validate({
rules: {
OpenIdTextbox: "required",
NicknameTextbox: {
required: true,
remote: "resources/nickname.aspx"
},
EmailTextbox: {
required: true,
email: true
}
}
});
});

I scratched my head for a long long time when i used ctl00_ContentPlaceHolder1_EmailTextbox and nothing worked at all. So what you have to do is change this to something like this ..

$(document).ready(function() {
// validate signup form on keyup and submit
$("#aspnetForm").validate({
rules: {
ctl00$ContentPlaceHolder1$OpenIdTextbox: "required",
ctl00$ContentPlaceHolder1$NicknameTextbox: {
required: true,
remote: "resources/nickname.aspx"
},
ctl00$ContentPlaceHolder1$EmailTextbox: {
required: true,
email: true
}
}
});
});

You could of course also use some method that rewrite the Control.UniqueID to a name and use <%= %> to get the name of the control.