[Serializable] DB.NET

Google apps - cheap alternative to mail server upgrade

2007-03-29T22:33:00.000+01:00

This is sort of old news, but still worth mentioning as it doesn't seem to be very popular at the moment.
Do you have a cheap, modest hosting and do you like gmail? If yes, then you will love this:
Google offers a free Google apps membership for "families and groups". What's the catch? Well, you can keep your cheap hosting but use the a google email server, with a 2 GB mailbox and all the features of a gmail-like webmail on top, for free. All you need to do is sign up and then change your MX records with your host's DNS (they will probably do that for you, most hosts do because at the end of the day it only means less traffic on their server).
I no longer use this because I got a better webhost this year, but I tried it and I loved it.

Row level validation in a gridview

2007-03-23T22:40:00.000Z

A couple days ago a friend asked me how can you make the ASP.NET validators validate the contents of a gridview at row level, so that each row works independently. For example, in the grid below use a requiredfieldvalidator on each row so that the Save button would validate the description textbox on the same row, but wouldn’t validate any of the other rows’ descriptions.

In this case, clicking the save button in the “Dairy products” row would cause the validation to suppress the postback, but clicking the save button of any other row wouldn’t.
The solution is simple: use the validation group bound to a unique row identifier. In our example (which displays the contents of the Categories table of the Northwind database) the binding would look like:

(asp:TextBox Width="300px" ID="txtDescription" runat="server" Text='(%# Bind("Description") %)' /)
(asp:RequiredFieldValidator ID="reqDescription" runat="server" ControlToValidate="txtDescription" ErrorMessage="*" ValidationGroup='(%# Bind("CategoryID") %)' /)
(asp:Button ID="butSave" runat="server" Text="Save" ValidationGroup='(%# Bind("CategoryID") %)' /)

The parenthesis ( ) should be replaced with less-greater than signs < >, they are just a workaround the poor blogger’s editor.

Download sample

Script controls may not be registered before PreRender

2006-11-22T13:24:00.000Z

This is neither a very common scenario nor a major finding, just a small reminder/warning to spare you a little debugging for one of those things that are fairly obvious yet could take some time to see.
While helping a friend figure out why his ASP.NET no longer works after "atlasising" it I came across this issue:
The page was throwing the following exception:

Script controls may not be registered before PreRender.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Script controls may not be registered before PreRender.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: Script controls may not be registered before PreRender.]
Microsoft.Web.UI.ScriptControlManager.RegisterScriptControl(TScriptControl scriptControl) +144
Microsoft.Web.UI.UpdateProgress.OnPreRender(EventArgs e) +140
System.Web.UI.Control.PreRenderRecursiveInternal() +77
System.Web.UI.Control.PreRenderRecursiveInternal() +161
System.Web.UI.Control.PreRenderRecursiveInternal() +161
System.Web.UI.Control.PreRenderRecursiveInternal() +161
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1360

As the page worked before it had the atlas references and an update panel added (and out of laziness) instead of properly reading the source code I proffered to google the error and the only relevant result was http://forums.asp.net/thread/1471314.aspx where the suggestion was that an older version of the DLL might be cached somewhere. Here is where I went wrong and spent a lot of time clearing and rebuilding. On a second look, I found that the page's OnPreRender method was overridden and it didn't call the base OnPreRender method therefore loosing some handlers. Obviously this mistake didn't do much difference before atlas came into play but it did afterwards because the Atlas ScriptControlManager's RegisterScriptControl method doesn't register the control but after prerender (by checking a flag it sets on prerender)

public void RegisterScriptControl(TScriptControl scriptControl) where TScriptControl: Control, IScriptControl
{
if (scriptControl == null)
{
throw new ArgumentNullException("scriptControl");
}
if (!this._pagePreRenderRaised)
{
throw new InvalidOperationException(AtlasWeb.ScriptControlManager_RegisterScriptControlTooEarly);
}
this.ScriptControls.Add(scriptControl);
}

public void OnPagePreRender(object sender, EventArgs e)
{
this._pagePreRenderRaised = true;
}

Unable to preview web service

2006-11-21T19:56:00.000Z

Seldom, but still a possible scenario: when trying to preview the generated service description for an asmx web service (both .NET 1.1 and .NET 2.0) you might get an error that is not very well described:

Line 1334: OperationBinding FindHttpBinding(string verb) {
Line 1335: foreach (ServiceDescription description in serviceDescriptions) {
Line 1336: foreach (Binding binding in description.Bindings) {
Line 1337: HttpBinding httpBinding = (HttpBinding)binding.Extensions.Find(typeof(HttpBinding));

The real issue is that in your web application’s web.config file in the pages element you probably have the autoEventWireup attribute set to false
<pages … autoEventWireup="false"…

If you want to trace the problem, you can open the DefaultWsdlHelpGenerator.aspx file (located under %windir\Microsoft.NET\Framework\[version]\CONFIG\DefaultWsdlHelpGenerator.aspx) and you would notice that the error is that the serviceDescriptions member is used without being initialized (therefore the null object reference exception). Looking up in the page you notice that the serviceDescriptions member is initialized
(as:
serviceDescriptions = (ServiceDescriptionCollection) Context.Items["wsdlsWithPost"];
or
serviceDescriptions = (ServiceDescriptionCollection) Context.Items["wsdls"];)
in the Page_Load method. However, because your settings disable the autoeventwireup that prevents the Page_Load methods from being called (it is not explicitly wired to the page load event so it relies entirely on the autoeventwireup feature).

Surely this isn’t a big finding and it wouldn’t save you more than 5 minutes of debugging but it is worth mentioning because it is a “red wiring” in the framework.

.NET Framework 3 is here

2006-11-07T20:13:00.000Z

After loosing several things, such as its name (looks like the petition to keep the "WinFX" name wasn't considered), object spaces, LINQ/DLINQ/XLINQ/BLINQ, C# 3.0 (which is promised in the final version of Orcas), finally .NET framework 3 is here now. I guess I'm not the only one who had to descope stuff this sprint ;)
With no direct connection, Atlas beta 2 and november CTP (another name lost on the way) is now released:
ASP.NET 2.0 AJAX Extensions Beta 2
ASP.NET AJAX Futures November CTP
ASP.NET AJAX Samples

Minor bug in WF 3.0 RC1 designer

2006-10-06T00:34:00.000+01:00

As stated in my previous post, the WF designer in version beta 2.2 was poor. It was very slow and came up with some non-sense error every 10 minutes or so. The changes in version 3.0 RC are obvious: the designer is still a bit slow but very stable. You can hardly fault it. However, I've noticed a small bug: if you define an event arguments class derived from ExternalDataEventArgs and use it to wire up an event to a handleExternalEventActivity even though it does compile and work just fine the designer shows it as an error (as shown in the image).

Let's take an example. We define an event arguments class inherited from ExternalDataEventArgs such as:

[Serializable]
public class MyExternalDataEventArgs : ExternalDataEventArgs
{
public MyExternalDataEventArgs(Guid instanceID) : base(instanceID)
{
}
}

Then we define the data exchange interface:

[ExternalDataExchange]
public interface IExternalEvents
{
event EventHandler MyEvent;
}

and then we create a workflow, drag a handle external event activity on the flow and wire it to our IExternalEvents interface and MyEvent event - which translates to:

this.handleExternalEventActivity1.EventName = "MyEvent";
this.handleExternalEventActivity1.InterfaceType = typeof(DerivedWorkflowClass.IExternalEvents);
this.handleExternalEventActivity1.Name = "handleExternalEventActivity1";

Now we can see the error icon, but still we can build the project with no problem, not even a warning.

That being said, sometimes as you come in and out of the designer the error icon disappears and the re-appears, but I couldn't see any patter in this behavior and most of the times the error icon is on.

This issue comes up on RC1 of .NET Framework 3.0 Runtime Components using:
Extensions for Windows WF
Windows Workflow Foundation Tools for Visual Studio

Orcas Technology Preview - .NET Framework 3.0 Development Tools 1.0
Microsoft Visual Studio Code Name Orcas Community Technology Preview - Development Tools for WinFX

I will report the bug on http://connect.microsoft.com/wf tomorrow. However, my point here is that after a month of pretty intense development on WF 3 RC1 this is the only bug I've found and as you can see it is a minor inconvenient so I guess it backs up the previous post proving that it is a stable release.

What's new in WF 3.0 RC

2006-10-03T00:11:00.000+01:00

Don't trust the title, it is misleading. This isn't a real "what's new" article, and I won't bother you with obvious things, such as the removal of FaultHandlerActivity's Fault property setter ... CompensatableTransactionScopeActivity (I thought I use to make up long class names), blah blah blah ... you could read that on http://wf.netfx3.com/ or on Paul Andrew's blog or so on... I just mean to express my surprise on the changes in the WF designer! It is 1000 times more stable and you don't get as many silly errors, and maybe it's just me but I feel it's even moving faster. Cheers for that!
It's amazing how (without acknowledging it) those small fixes in the flaky designer build up your confidence.

Event code snippet

2006-10-02T21:44:00.000+01:00

Indeed, most times you write the events at a time, maybe in a region and the trigger methods afterwards in another region; but then you do the same with local fields and properties, and yet the prop snippet comes in handy. Therefore I thought a simple event code snippet would be useful. You can download it here and then copy it to your Program Files\Microsoft Visual Studio 8\VC#\Snippets\1033\Visual C#\ directory

<?xml version="1.0" encoding="utf-8" ?>
<CodeSnippets xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
<CodeSnippet Format="1.0.0">
<Header>
<Title>event</Title>
<Shortcut>event</Shortcut>
<Description>Code snippet to created and document an event</Description>
<Author>Daniel Balla</Author>
<SnippetTypes>
<SnippetType>Expansion</SnippetType>
</SnippetTypes>
</Header>
<Snippet>
<Declarations>
<Literal>
<ID>event</ID>
<ToolTip>Event name</ToolTip>
<Default>MyEvent</Default>
</Literal>
<Literal>
<ID>eventArgs</ID>
<ToolTip>Event arguments type</ToolTip>
<Default>EventArgs</Default>
</Literal>
</Declarations>
<Code Language="csharp"><![CDATA[#region Event Handler $event$ ($eventArgs$)
/// <summary>
/// This event is fired when |
/// </summary>
public event EventHandler $event$;
#endregion
#region Event notification $event$
/// <summary>
/// Notifies the listeners of the $event$ event
/// </summary>
/// <param name="e">The argument to send to the listeners</param>
protected virtual void On$event$($eventArgs$ e) {
if($event$ != null) {
$event$(this,e);
}
}
#endregion$end$]]>
</Code>
</Snippet>
</CodeSnippet>
</CodeSnippets>

Dependency property code snippet

2006-09-05T16:10:00.000+01:00

As I came across the dependency property (which hit me right when I started developing WinFX) I've created this code snippet to spare me of writting the code every time (the dependency property and the backing property).
You can download it here and then copy it to your Program Files\Microsoft Visual Studio 8\VC#\Snippets\1033\Visual C#\ directory
or you can copy/paste the snippet:

<?xml version="1.0" encoding="utf-8" ?>
<CodeSnippets xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
<CodeSnippet Format="1.0.0">
<Header>
<Title>dprop</Title>
<Shortcut>dprop</Shortcut>
<Description>Code snippet for dependancy property and backing property</Description>
<Author>Daniel Balla</Author>
<SnippetTypes>
<SnippetType>Expansion</SnippetType>
</SnippetTypes>
</Header>
<Snippet>
<Declarations>
<Literal>
<ID>type</ID>
<ToolTip>Property type</ToolTip>
<Default>string</Default>
</Literal>
<Literal>
<ID>property</ID>
<ToolTip>Property name</ToolTip>
<Default>MyProperty</Default>
</Literal>
<Literal Editable="false">
<ID>classname</ID>
<ToolTip>Class name</ToolTip>
<Function>ClassName()</Function>
<Default>ClassNamePlaceholder</Default>
</Literal>
</Declarations>
<Code Language="csharp"><![CDATA[public static DependencyProperty $property$Property =
DependencyProperty.Register("$property$",
typeof($type$), typeof($classname$));

public $type$ $property$
{
get { return (($type$)base.GetValue($property$Property)); }
set { base.SetValue($property$Property, value); }
}$end$]]>
</Code>
</Snippet>
</CodeSnippet>
</CodeSnippets>

WinFX or .NET 3.0 ?

2006-08-30T15:20:00.000+01:00

Should it be named WinFX or .NET 3.0?
I belive WinFX.
That's why I just signed this petition . I agree to most points in it and I do belive that naming it .NET 3 is just a lame marketing decision.

First experience with WWF

2006-08-29T17:16:00.000+01:00

This is just an initial contact with WWF and here are a few links that I found usefull to get myself familiar with it:

http://wf.netfx3.com
http://msdn.microsoft.com/winfx/technologies/workflow/default.aspx#wwfi_topic3
Muke Taulty's blog
WWF vs Biztalk
ASP.NET & Workflows by Dino Esposito
more WWF by Dino Esposito
the 4 episodes of DNT TV on WWF
MSDN TV WWF episode

Issues still outstanding:

didn't find any proposed naming conventions or design guidelines
still didn't figure out how to overcome the bug in version beta 2.2 that eventually causes the build error 'The item "obj\Debug\......" was specified more than once in the "Resources" parameter. Duplicate items are not supported by the "Resources" parameter.'

Stress testing web services with WAST through SOAP

2006-08-15T13:33:00.000+01:00

Stress testing webservices: I just found this great article on how to use Ms WAST with SOAP. In this manner, this looks like a decent tool to stress test web services (if you don't have VSTF). If anyone reading this has a better idea please do leave a comment.

steepvalley.net: XPCC Introduction

2006-04-30T14:27:00.000+01:00

Bookmark:
steepvalley.net: XPCC Introduction
Great win forms controls for both 1.1 and 2.0.

Optimized ASP.NET DataGrid Sorting - The Code Project - ASP.NET

2006-04-30T14:26:00.000+01:00

Bookmark:
Optimized ASP.NET DataGrid Sorting - The Code Project - ASP.NET
This is a simple yet very efficient implementation of a .NET 1.1 datagrid.
my TO DO: create a template project (wizard) with this as it does come in handy.

Credit Card Electronic Payment Processing with ASP.NET

2006-04-24T17:25:00.000+01:00

Processing credit card is always an important aspect of an e-commerce web site. I am not an expert on this matter, but this is what I found so far:

Credit Card Electronic Payment Processing with ASP.NET: "Integrating Electronic Payment Processing into
ASP.NET Web Applications"

Good alternative for fancy sites. Otherwise, just stick with 2checkout.com
It's not the most elegant because it's not white labeled (actually it doesn't fit in the client web site at all) but it works, and it's cheap.

.NET Application Updater Component

2006-03-06T21:11:00.000Z

I didn't previously used this, but it is great! even better than the newer Click Once technology.
A nice open source project using it: TaskVision.

more: .NET Application Updater Component

still to compare with: http://www.codeproject.com/useritems/WebUpdate.asp

Adam Cogan's Rules

2006-03-04T16:28:00.000Z

Ok, although I have always been drawn towards code standardization ,patterns and rules, I must admit I never dreamed of such a level of rules standardization. This guy has done it all, and further more he standardized every process and build tools to automate the rules implementation in the development process (Adrian, are you reading this?)
I do wonder if I should build my own tools or buy his :)
These are just a few of many:
SSW Rules to Better Websites - Development
SSW Rules to Better Google Rankings
SSW Rules to Better .NET Projects

.NET Rocks! hosted by MSDN

2006-02-19T14:37:00.000Z

This is a good show I've been missing. what a shame !
.NET Rocks! hosted by MSDN
I got to save this link

Default Button Submissions in ASP.NET Pages - Rick Strahl's WebLog

2006-02-18T21:37:00.000Z

Good point: default button on ASP.NET 1. Great solution:

Default Button Submissions in ASP.NET Pages - Rick Strahl's WebLog

even better in .NET 2 (supports default button)

Good (& free & open source) asp.net controls

2006-02-18T21:09:00.000Z

available here: http://www.metabuilders.com

2005-11-08T08:30:00.000Z

Great wizard, one of the best lost & found links: http://www.arstdesign.com/articles/sdimdiwizards.html

ASP.NET AJAX component

2005-10-31T15:31:00.000Z

A man with a plan: Jason Diamond
He built an AJAX ASP.NET component library, open source (the only one that I am aware of) and he took it to release 12 !
Nice job !
Speaking of, I am pondering at a very interesting concept: a sort of Portal starter kit (like IBuySpy portal) with AJAX. Are you up to it? if so, leave a comment, maybe we can gather a team.

Must read :: ASP.NET & AJAX

2005-10-30T20:41:00.000Z

Great article (low level, yet good) about AJAX & ASP.NET

read me

Must read :: Improving Application Performance by Implementing Paginated Lists

2005-10-30T20:40:00.000Z

Describes how Ameripay has implemented the "How To: Page Records in .NET Applications" section of the Microsoft patterns & practices book Improving .NET Application Performance and Scalability

read here

more info on the subject can be found here

2005-10-29T16:06:00.000+01:00

Nice book: http://www.brpreiss.com/books/opus6/html/book.html