Springboard Pillow

Sunday, March 15, 2009

Some bluetooth resources. Rage.

Just some links to various useful sites for bluetooth...

http://blog.opennetcf.com/

http://blog.opennetcf.com/ctacke/2008/12/23/SDF23ControllingRadioPower.aspx

http://weblogs.asp.net/skillet/archive/2005/06/23/414626.aspx

http://msdn.microsoft.com/embedded/usewinemb/ce/sharedsrccode/west/default.aspx

http://32feet.net/

http://channel9.msdn.com/wiki/bluetoothdevelopment/

http://msdn.microsoft.com/windowsmobile/downloads/videos/default.aspx

There does seem to be a lot of niche interest in bluetooth, but MicroSoft are letting developers down by not providing a bluetooth API for Windows and Windows Mobile. How beautiful it would be to create a solution with a couple of Win Forms and Mobile Forms app projects and use the same API in both to communicate over bluetooth, serial even IR. But no. There are even videos available on Channel9 where MS devs talk about the amazing work they've done using the MicroSoft C# bluetooth API but simply don't make any of the useful information available. What's going on MS? Is it because you know BT is destined for the bin? And no, I don't consider the above link to Channel9 a productive one. Is that really the best MS can for us? Anil Dhawan's link is broken!

Gizmodo, gadgets and fun in the news...

Just browsing about today, I thought I'd post this as it's a bit of a laugh...

http://i.gizmodo.com/5169391/10-gadgets-that-help-you-retain-your-masculinity?skyline=true&s=i

Photo info for creating high dynamic range images...

http://i.gizmodo.com/5168454/how-to-create-stunningly-realistic-high-dynamic-range-photographs?skyline=true&s=x

Mars!

http://i.gizmodo.com/5170120/live-images-from-google-mars-now-available

Friday, March 13, 2009

Tips 'n' Tricks - Null Coalescing Operator

We all like the null coalescing operator (http://msdn.microsoft.com/en-us/library/ms173224.aspx), but it’s frustrating when we need to set the variable we’re returning rather than just returning it.

Really we just want to do this:

public class Something
{
private string falafel;

public string GetInfo()
{
return falafel ?? "tabbouleh";
}
}

But then falafel doesn’t get set.

This feels inelegant:

if (falafel == null)
falafel = "tabbouleh";
return falafel;

Luckily, there’s a solution:

return falafel ?? (falafel = "tabbouleh");

This first sets the value of falafel and then returns it.

Wednesday, March 11, 2009

Fun With GridView...

[EDIT: This is being posted now, but was started back in 2006, so might be a little out of date. My aim is to have no draft posts and this was too useful to delete.]

So I've been playing with databinding controls etc and trying to do things the easy way, I've discovered CodeSmith: http://www.codesmithtools.com/. Used in conjunction with NetTiers2: http://www.nettiers.com/ is a very powerful data access layer code generator.

Anwyay, todays subject, minor though it is, is GridView commands...
...I wanted to have a grid with a couple of buttons: Up and Down, as link buttons, to re-order my content without an edit button.

The solution is simple enough:

Add a Button column to your GridView
Set it's 'button type' to Link (this is optional really)
In the GridView's events panel, double-click RowCommand
In the generated event handler you can place:
switch (e.CommandName) { .... }

Simple really.

Lastly, here's some resources I've been looking at recently:

Caching and Url Mapping

Caching.

If you look at the line <%@ OutputCache... in the .aspx files you will see that it is configured to cache the output of that whole page for the value in the Duration attribute. The VaryByParam value indicates that any url parameter will cause the page to be re-generated and cached. Replace the "*" with "none" and the caching will ignore the url params and that page will be cached once for the duration.
The OutputCache can be used in individual user controls as well, however, if the page has a duration of 20 and the control within it has a duration of 10 both will be cached for 20. Reverse those numbers and the page will be cached for 10 but the control will be cached for 20.

Be careful that you don't try to reference in your code a control which may have been cached, as it will come back with a null reference, possibly causing an exception!
One other method of caching is substitution mapping, the drawback being that you can only point this at .net controls, not user controls.

Url Mapping.

Now, go to IIS, create a virtual directory under Default Web Site, point it at the Test solution's directory. Open the Properties panel for the virtual dir. Do the following:
Disable directory browsing.
Under Documents, enable default document and have only 1 default document called default.aspx.
Go back to Virtual Directory, click Configuration, click Add and enter:
1. Executable: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll
2. Extension: .*
3. All Verbs
4. Script Engine ticked
5. Check that file exists NOT ticked
6. Click Ok, Click Ok.
Go to ASP.NET tab and ensure the ASP.NET version is 2.0.50727
Click Ok.
Now, when you browse to http://localhost/test/lose/ or http://localhost/test/win/ you should see the page come up which is actually /test/win.aspx or /test/lose.aspx. Hit refresh and you will see the time has not changed, because the page has been cached. The page appears, even though you have entered a directory name, because IIS is automatically adding default.aspx to any requested directory listing and redirecting all file requests to the .net framework. The .net framework is redirecting from ~/win/ or ~/lose/ to ~/win.aspx or ~/lose.aspx because in the web.config you have a UrlMapping block! Easy.

The only problem with this is that you can't use regular expressions to have, for example, ~/search/ipod/ re-mapped to ~/search.aspx?query=ipod which is annoying, but only because the next server version from microsoft will have a fully operational url mapper and they didn't have time to put it into the current release.

Links:

Caching: http://msdn2.microsoft.com/en-us/library/xsbfdd8c.aspx
Substitution mapping: http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.substitution(VS.80).aspx
Url Mapping: http://www.developer.com/net/asp/article.php/3581326
MS Blog: http://weblogs.asp.net/scottgu/archive/2005/11/14/430493.aspx

Tuesday, March 10, 2009

Tools List

Here's a list of tools which I use on a regular basis and would be a fixture of a Windows image, if I ever create one...

I had a slightly different list previously: http://springboardpillow.blogspot.com/2009/03/tools-list.html

Rubberduck Debugging

Got this from our work email, if you like "intra-mail"...

http://lists.ethernal.org/oldarchives/cantlug-0211/msg00174.html

We called it the Rubber Duck method of debugging.  It goes like this:

1) Beg, borrow, steal, buy, fabricate or otherwise obtain a rubber duck    (bathtub variety)

2) Place rubber duck on desk and inform it you are just going to go over    some code with it, if that's all right.

3) Explain to the duck what you code is supposed to do, and then go into    detail and explain things line by line

4) At some point you will tell the duck what you are doing next and then    realise that that is not in fact what you are actually doing.

The duck    will sit there serenely, happy in the knowledge that it has helped you    on your way.  Works every time.  Actually, if you don't have a rubber duck you could at a pinch ask a fellow programmer or engineer to sit in.

A university in Canada I was told about many moons ago actually had a teddy bear sitting in the student admin's office. When a student wished to book in with a lecturer to discuss a problem they were asked if they'd explained their problem to the teddy bear. If they hadn't, they were told to do that first. This cut something like 80% of lecturer meeting requests from students.

Monday, March 09, 2009

ASP.NET Life Cycle Diagram

Just a quicky... It's often nice to know what the steps are in the ASP.NET life cycle, as we all forget this (probably) easily and often, especially if we stop using it for a while...

So here is a link providing some good life cycle diagrams:

http://images.google.com/images?rlz=1C1CHMB_en-GBGB316GB316&sourceid=chrome&q=asp.net%20life%20cycle&um=1&ie=UTF-8&sa=N&hl=en&tab=wi

My favourites:

http://www.eggheadcafe.com/articles/o_aspNet_Page_LifeCycle.jpg

http://blogs.vertigosoftware.com/shannonf/archive/2005/08/07/1355.aspx

http://sanal.org/story/download-aspnet-ajax-client-life-cycle-events-cheat-sheet/

http://blog.codeville.net/blogfiles/2007/ASPNET-MVC-Pipeline/ASP.NET%20MVC%20Pipeline.pdf

http://spazzarama.files.wordpress.com/2009/02/aspnet_page-control-life-cycle.jpg

And one general use link:

http://www.cheat-sheets.org/

He he he!

Creating a certificate in IIS

This is an easy one and really specific to developers who need to do this and only this, but essentially I found the answers by googling "SelfSSL" and "IIS certificate"...

You will need to do this if you want a website hosted in your local IIS which uses HTTPS.

[EDIT: 21/04/2009] If you need a network certificate from an online (or your company's domain) authority, you should Request a Certificate. Microsoft provide fairly easy instructions for this here: http://support.microsoft.com/kb/228821

If you can't locate SelfSSL.exe on your own machine, I've a compressed version you can download here: http://home.freeuk.com/eudoxus/selfssl.rar

[EDIT:01/04/2009] I've just located the download page for this, along with some helpful articles:

IIS Resources Toolkit download: http://www.microsoft.com/downloads/details.aspx?FamilyId=56FC92EE-A71A-4C73-B628-ADE629C89499&displaylang=en
IIS Resources help page: http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/993a8a36-5761-448f-889e-9ae58d072c09.mspx?mfr=true
Google search for IIS resources information: http://www.google.com/search?hl=en&rlz=1C1CHMB_en-GBGB316GB316&q=iis+resources&btnG=Search

For a site I setup recently, I used the following line:

selfssl.exe /N:CN=mytestsite /K:1024 /V:1000 /S:30412573 /P:443 /T

Broken down thus:

selfssl.exe

/N:CN=(sitename - doesn't have to match anything)

/K:(certificate size in bytes)

/V:(expiration period in days)

/S:(site id, found by selecting 'Web Sites' in IIS and checking the 'Identifier' field on the right)

/P:(https port number, leave it at 443)

/T (adds the certificate to the trusted sites list)

Once this is finished, open the Properties panel for the website you've just added a certificate to and go to: Web Site -> Advanced -> Multiple SSL identities for this Web site

In this area you should see that the IP address is 'Default' and the SSL port is '443'. Double click this row (or select and click Edit) and replace the 'Default' IP address entry with the IP address of the web site you created.

This last piece means that when the browser goes to the site looking for a secure page IIS will direct it towards the same site, ie the same IP address, rather than the default (the machine address.) You could create two sites, under different IP's, one secure and one not, but that will make your site building harder as you'll have to cater for this in various ways (that I won't go into.)

Have fun.

[EDIT:18/03/2009] It is my experience (Windows 2003 Server R2, IIS 5.2) that occasionally IIS will need the certificate recreating. I don't know why, but I'll try to document it here if I find out.

[EDIT:01/04/2009] Just been sent this: http://support.microsoft.com/kb/260096

The issue being wrestled with here is that (since version 5.0) when IIS starts up it begins listening for all sites on ports 80 and 443 (standard web and SSL) for incoming connections. This is known as socket pooling. This means that only the first site with SSL (ie: the last site to have a certificate registered) will receive requests on HTTPS. This can be turned off by following the link in the second section (of the above page), which you can also find here: http://support.microsoft.com/kb/259349/EN-US/ Please read both these pages to be fully informed, but for brevity, here are the steps to disable socket pooling:

At a command prompt, switch to the "C:\InetPub\AdminScripts" folder.
Type the following command:
CSCRIPT ADSUTIL.VBS SET W3SVC/DisableSocketPooling TRUE

You can also read more about this at: http://support.microsoft.com/kb/238131/EN-US/

Just for reference, I've switched off socket pooling on my machine using the article above and it looked something like this:

C:\>cd Inetpub

C:\Inetpub>cd AdminScripts

C:\Inetpub\AdminScripts>CSCRIPT ADSUTIL.VBS SET W3SVC/DisableSocketPooling TRUE
Microsoft (R) Windows Script Host Version 5.6
Copyright (C) Microsoft Corporation 1996-2001. All rights reserved.

DisableSocketPooling : (BOOLEAN) True

C:\Inetpub\AdminScripts>

Augmented Reality in CSharp

My mind was completely blown away last night when I discovered a blog post by a guy called Casey providing wrapped C++ code for a simple augmented reality project in C#:
http://www.mperfect.net/wpfAugReal/

This is a first step, but it provides a source code solution in .NET to render 3D objects over a live webcam video feed.

To get it running just make sure you have a webcam with a clean image, .NET 2.0 and Visual Studio, the WPF (Windows Presentation Foundation) installed, and DirectShowLib. These are all linked from the above link.

I really hope this can be expanded on and that Casey does not mind me referencing his code because the more interest there is in this, the faster/more practical it will grow and become. We don't see really exciting creations like this in everyday life very often, but hopefully this will establish itself.

Btw, one I've not checked out properly: http://sites.google.com/site/augmentedrealitytestingsite/

Resources:

DirectShow API on WikiPedia: http://en.wikipedia.org/wiki/DirectShow
DirectShow Article at CodeProject: http://www.codeproject.com/KB/directx/directshownet.aspx
TotalImmersions AR video: http://video.google.com/videoplay?docid=6523761027552517909
Also, a skeleton C# AR app: http://sites.google.com/site/augmentedrealitytestingsite/

Thursday, March 05, 2009

ASP.NET Globalization, Culture, Localization and the Resource tag

So here's a couple of useful links that involve setting the appropriate properties of websites in ASP.NET that every .NET coder should be aware of. Also, something I only recently discovered proper is the tag. Looks like I've some reading to do, may well expand this entry another time...

ASP.NET Globalization and Localization:

http://msdn.microsoft.com/en-us/library/c6zyy3s9.aspx

Basic Instincts-Resources and Localization in ASP.NET 2.0: http://msdn.microsoft.com/en-us/magazine/cc163566.aspx

Original Basic Instincts article: http://msdn.microsoft.com/en-gb/magazine/cc163609.aspx

Extract:

In addition to programmatic access, ASP.NET 2.0 also introduces declarative syntax you can use to bind a named string to a property of a page or control. The syntax involves using the dollar sign ($) followed by the Resources namespace, the name of the resource file and the name of the string:

Wednesday, March 04, 2009

Tweet tweet tweet...

Yes, I now twitter...

Me: http://twitter.com/horacebury

Others: http://www.hanselman.com/blog/HowToTwitterFirstStepsAndATwitterGlossary.aspx

Tools: http://blendingthemix.com/2009/01/23/the-most-popular-100-twitter-applications/

Mobile: http://m.twitter.com/home

Auto: http://twitterfeed.com/

Commerce Server, Afraid to ask?

Finally getting into Microsoft Commerce Server for work and have been looking around for useful articles to break me in gently. Some good posts from Max Akbar right here:

http://blogs.msdn.com/maxakbar/search.aspx?q=pipeline+afraid&p=1

The initial thrust of my exploration is Pipelines, hence the first 4 articles in the above search, but the rest is good reading.

gacutil exited with error 9009

Ok, this isn't one for me, right now, but I noticed this occuring in some code I'm working on. Now, I don't mess about with the gac (global assembly cache) in .NET - I'm a straight shooter - but I also like to note down issues with resolutions that might crop up later.

Henceforth, here is a blog post with a useful link:

http://blogs.interakting.co.uk/dominicz/archive/2007/09/17/gacutil-exited-with-code-9009.aspx

And the article with the solution (original link):

http://groups.google.com/group/microsoft.public.vsnet.general/browse_thread/thread/6e1d0137b0845dcb/1ac407ec67873ceb?lnk=gst&q=9009&rnum=2&pli=1

Essentially, it's useful to be aware that VS does not take into account environment variables when compiling code unless executed with the right options, so best to use the full pathname of assemblies.

Tuesday, March 03, 2009

Quake? Online? In a browser window? Nice(?)

Ok, so I just noticed this little beauty on my Google homepage:
http://www.hanselman.com/blog/QuakeLiveReviewAndRantWhyIsThisInteresting.aspx

However, hmm, looks like it'll be a disappointment. Better stick with Unreal 3 ;)

Thursday, February 19, 2009

Convert byte[] to String

I was going to make one big entry containing lots of little bits of code, then realised I only had one to put in, because I keep forgetting it...

Converting a byte[] (array) into a String:

string outStr = System.Text.Encoding.UTF8.GetString(inByteArr);

Thursday, February 12, 2009

Friday, January 23, 2009

More Embedded Resource fun

If you're new to embedded resources please read this entry first: http://springboardpillow.blogspot.com/2009/01/embedded-resources-and-having-fun-with.html

Now we'll use the same image, from my previous blog entry, from within the project we created earlier. For this we will need a...

Custom Web Control

To make this, either use the default ServerControl1.cs, or right click the control project and select: Add -> New Item -> Web -> ASP.NET Server Control. By default this should give us:

WebCustomControl1.cs

To get in the habit, first...

Compile the Control Project

Select: Build -> Rebuild [project name]

This will recompile the custom web control project, including the new (empty) control and place it's DLL into the web project. This is because we previously referenced the control project from the web project. Now, we are going to...

Add a reference to the Embedded Resource to the Custom Control

In the new custom control, find the RenderContents(...) method and replace it's content with:

output.Write(
"<img src='"+
Page.ClientScript.GetWebResourceUrl(typeof(EmbeddedCtrls.ServerControl1),"EmbeddedCtrls.cartman.jpg")+
"' />"
);

You should be able to see that this is essentially just manually writing out the same code as was in the previous web page, however this time we are inside the custom control and so the reference to it can essentially be 'this.GetType()'.

Now, rebuild the custom control project as before (Build -> Rebuild [project name]) and the updated DLL will be copied to the web project. All we need to do is...

Drop the Custom Control onto a Web Page

So, create a new ASPX in the web project and open it's design view. If the custom web control project compiled correctly, you should have a new toolbox group called '[project name] Components'.

Grab the custom control from within the toolbox group and drop it onto the designer. Save everything and run the page.

You should now have the same output as in the previous blog entry!

Easy, eh?

Two things to Note are...

That dropping the custom control on your web page add a Register directive to the top (just as any ASP.NET toolbox control does)

And that you will have a <span> tag surrounding your <img> tag. To remove this, simply override RenderBeginTag and RenderEndTag, like so:

public override void RenderBeginTag(HtmlTextWriter writer)
{
// removed one line of default code!
}
public override void RenderEndTag(HtmlTextWriter writer)
{
// removed one line of default code!
}

Listing the Known Embedded Resource

If you want to place a stop point in your code and list the embedded resource files that are available to you, paste the following line just before your stop point:

object a = GetType().Assembly.GetManifestResourceNames();

Upon stopping here, the 'a' object will be a list of embedded resources.

As Before...

The entire demo solution can be found here.

Resources:

http://support.microsoft.com/kb/910442
http://www.codeproject.com/KB/aspnet/MyWebResourceProj.aspx
http://aspnet.4guysfromrolla.com/articles/080906-1.aspx
http://aspalliance.com/726
http://msdn.microsoft.com/en-us/library/yhzc935f.aspx

Embedded Resources and having fun with them

Ok, so, having gotten back from 2 months round the world and almost 3 months not coding at all, I'm feeling rusty. Opening Visual Studio came as quite a shock, simply because "All Those Buttons Can't Possibly Do What I Remember!!!"

Anyway, back in the saddle (I hope) and getting some new code under my belt: This time in the form of...

Embedded Resources

What are those? Well, when you drop, say, a GridView control or something, anything from the toolbox onto your page and it already has, lets say, stylesheets, images, javascript etc, that you think would be better provided as separate files... they probably are. How? Well, when building the code as separate files the non-C# files are placed into an...

ASP.NET Server Control project

This project then needs to be referenced by the web project, so that it's DLL is placed in the website's \bin directory, thus placing any (correctly compiling) custom web controls [because that's what this project type is for] into the toolbox (when ASPX/ASCX 's are in design mode.)

So, lets...

Create a Custom Web Control with images and stylesheets in a DLL

So, open Visual Studio and create a new solution (File -> New -> Project -> Visual C#|Basic -> ASP.NET Web Application) This will give us a website as well.

Now, to this solution, add an ASP.NET Server Control project (File -> Add -> New Project -> Visual C#|Basic -> Web -> ASP.NET Server Control) This gives us a project we can create custom web controls in. This is also the project where the embedded files will be placed.

Ok, so the quickstart to adding and using an embedded resource is...

Add an Embedded Resource and call GetWebResourceUrl

First we need something to use. So lets add an image to the control project - not the web project!

In order to make the image embedded select it in the solution explorer and in the properties panel change it's Build Action to Embedded Resource.

Now make the image usable by expanding the control project's Properties item (in the solution explorer) and edit the AssemblyInfo.cs. Add the following lines to the using declarations at the top:

using System.Web.UI;

And the following to them bottom:

[assembly: WebResource("EmbeddedCtrls.cartman.jpg","image/jpg")]

Where the format is:

[assembly: WebResource("[assembly name].[directory names].[filename]","[filetype]")]

For an image called "cartman.jpg" stored in the root directory of the control project.

Bear in mind that the first part is the assembly name (select the project in solution explorer and click properties) and not the namespace. Also, that rather than being a typical absolute path, the path separators are '.' and not '/'.

We now have a project with an image which can be referenced as an embedded resource, both by code within the control project and any project which references it's DLL's, eg: the web project we created at the start.

Important: One major stumbling block I found was that if the above line of code, in the AssemblyInfo.cs, does not get recognised by Visual Studio, it means something has gone when creating the project. Just delete it and create a new "ASP.NET Control Project". It should appear as so:

[assembly: WebResource("EmbeddedCtrls.cartman.jpg","image/gif")]

Or something close to that, assuming you haven't adjusted your editor styling.

Now, to actually use this image somewhere, we need to...

Add a reference to the Control Project and Compile It.

So, in the web project, right click the References and add the control project as a reference. Then, select the control project in the solution explorer and click Build -> Build [project name]

This will compile the control project and copy it's DLL into the web project's \bin directory. Nearly there. Finally, we need to use it by...

Adding a reference in a web page

Either add an ASPX or open the default one. Paste the following line into the <div></div> statement in the HTML of the page:

<img src='<%= Page.ClientScript.GetWebResourceUrl(typeof(EmbeddedCtrls.ServerControl1),"EmbeddedCtrls.cartman.jpg") %>' />

And run the web page. If everything goes to plan, you should have a page with a single img tag which displays your embedded image.

If WebResource.axd is not found, check the highlighting of the assembly: webresource statement as described above. Also, check that the image file Build Action is set to Embedded Resource, in the properties panel. If the image simply fails to appear, just go through and check that you are providing the correct file name, assembly name, etc.

If you get a web resource exception, it's because you are not registering the embedded resources correctly. If you get a webresource.axd?d=... URL but it shows nothing, it's because the image file is not being referenced in your code properly. The GetWebResourceUrl call and the AssemblyInfo.cs entries must match.

Failing the above, ensure that each time you change the contents of the control project that you rebuild the project and refresh the web page. Simply recompiling the web project will not do it (unless you've configured your solution especially - this is not the default in VS.)

Wasn't that fun? You can download the complete solution here. That is also the same download for the next blog entry, where I will deal with referencing the image from within the control project.

Resources:

Saturday, October 04, 2008

Getting MVC setup

This is all about getting MVC Preview 5 running: http://www.codeplex.com/aspnet/Release/ProjectReleases.aspx?ReleaseId=16775

ASP.NET Project page: http://www.asp.net/mvc/

Had a bit of trouble getting MVC setup. A nasty little bugger going by the name of "Cannot load assembly ..." etc. You know the score.

One post on forums.asp.net sorted it all out:

http://forums.asp.net/p/1314519/2596828.aspx

I short, do the following:

Go to: C:\Documents and Settings\All Users\Start Menu\Programs\Microsoft\Microsoft Visual Studio 2008\Visual Studio Tools

Run: Visual Studio 2008 Command Prompt

Go to: C:\Program Files\Microsoft ASP.NET\ASP.NET MVC CodePlex Preview 5\Assemblies

Type:
C:\Program Files\Microsoft ASP.NET\ASP.NET MVC CodePlex Preview 5\Assemblies>gacutil -if System.Web.Routing.dll

And:
C:\Program Files\Microsoft ASP.NET\ASP.NET MVC CodePlex Preview 5\Assemblies>gacutil -if System.Web.Abstractions.dll

That should install the DLL's into the GAC (Global Assembly Cache) and cause .NET 3.5 to find them suitably.