Experiencias .NET

T-SQL: Concatenate something + null=null

2007-11-05T22:31:00.001+01:00

Today I have lost 2 hours until I have discovered this rule. I wanted to concatenate the contents of a field in the database with a variable using something like that:

UPDATE TableName

SET FieldName=FieldName + ',' + @value
WHERE ID=@ID

If the value of FieldName is null this operation is very stupid because the result will be null too. In my case I have forced that the field was not nullable (default value: '') and all runs.

Vertical Label

2007-10-30T18:45:00.001+01:00

Recently I have needed to display a label with the text in vertical direction. I have accomplished it using CSS with the next CSS class:

.verticaltext

{

writing-mode: tb-rl;

filter: flipv
fliph;

text-indent: 60;

padding: 2px;

height: 75px;

}

Accessibility, CSS Friendly Controls, AspNet Menu and IE6

2007-06-01T12:51:00.001+02:00

If you are developing an accesible site with ASP.NET 2.0 you can use the CSS Friendly Controls Adapters to render the controls without tables. You can access to the project at http://www.codeplex.com/cssfriendly. The current release of the AspNet Menu does not work with IE6 and the menus are invisible. After some investigation I discover that the problem is the Menu.css in the project. I have excluded this file and it shows the menu in IE6. Finally I have discovered what was happening. There is a bug in IE6 with the next class included in the Menu.css:

ul.AspNet-Menu

{

position: relative;

}

If you delete it all will works fine. For that reason I recommend to check the CSS files included in the project and verify it if you detect some strange behavior. In our case we have model the menu in the css of the application.

Special thanks to Edu and Victor who detect it.

Related Links:

http://www.codeplex.com/cssfriendly

Writing into Event Log from an ASP.NET application

2007-04-23T02:09:00.001+02:00

If you try to write an entry to events log form an ASP.NET application is probably that you find an exception like this "The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.". The reason is that the ASP.NET process cannot find the source of the entry. You have to create it manually because, by default, the ASP.NET process, cannot do it programmatically. To create it manually you have to add a new entry in the registry (regedit.exe) with the name of your source (in the example TEST under Application log) in the following path "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Application". Then, with the following code, you can write your entries.

string sSource;
string sEvent;
sSource = "TEST";
sLog = "Application";
sEvent = "Sample Event";
EventLog.WriteEntry(sSource, sEvent);

Related Links:
http://pranas.net/Tutorials/asp/EventLog.htm (example)

New certification

2007-03-09T23:44:00.000+01:00

Today I have passed the 70-528 (Microsoft .NET Framework 2.0 - Web-Based Client Development). It adds to my previous certification in Windows and web development on the .net framework 1.1 (70-316 & 70-315).
Personally I have found this last exam more util than the previous version due the more general questions.
If you are preparing this exam I recomend the books of Dino Esposito about ASP.NET 2.0.

CRCDISK.SYS

2007-02-16T11:08:00.000+01:00

After the last crash of my old XP I decided to install Vista on my Dell Latitude 610. I have installed Office 2007 and it was so pretty…

But when all were running perfectly during two days, this morning I could not start my notebook. After rebooting in safe mode it stopped at the load of the CRCDISK.SYS and 10-15 minutes later it continues with the boot process. Searching on the net I found a lot of posts about this issue, but apparently nothing could be applied to my notebook. Some posts talked about the external devices, other about the upgrade from XP and other about the energy supply. Then I remembered that the only suspicious thing that I had done about energy supply was to change de "Power Plan" of my machine from "Balanced" to "High Performance". Finally, I reverted this setting and all works.

Note: Now I am writing this post from Vista and directly from Word 2007. A great feature!

Creating a secure site using SSL

2007-02-05T18:30:00.000+01:00

I have found this utility to do it in less than 1 minute and the most important thing... WITHOUT TYPING! Its name is SSL Diagnostics Version 1.1 (x86) and you can get it from Microsoft. You only have to identify your IIS instance, right-click and choose Create New Cert.

Closing a terminal server sesison remotely.

2007-01-17T10:03:00.000+01:00

Several times I get an error when I try to conenct to a server through remote desktop. That is due to the number of termional server sessions on the server has been exceeded. My solution was to go to the phisical machine, log in and disconnect one of the sessions. But what happens if the machine is not accessible phisically.

Well there are two commands that will do my live easier: qwinsta and rwinsta. With qwinsta you can query the opened sessions in a server:
qwinsta /server:[IP | name]

rdp-tcp 65536 Escuchar rdpwd
rdp-tcp#2 Administrator 2 Activo rdpwd
rdp-tcp#4 Administrator 1 Activo rdpwd

With rwinsta you can reset the connections. You have to specify the server and the session ID.
rwinsta /server:[IP | name] id

In the last example we could reset the session with: rwinsta /server:NEO 2
Where NEO is the name of the machine and '2' is the session id.

For more administration utilities you can visit this page about sysinternals.

How was that connection string...?

2006-10-01T22:11:00.000+02:00

How many times have you made this question?
Well, in this page you can find all the connection strings that you need.

Creating users programmatically in DNN 4.3.5

2006-09-27T11:10:00.000+02:00

We had creted a custom registration module in DNN 4.0.3. When I updated my module to DNN 4.3.5 I found that this version had several changes.

The major issue I have found is the fact that I can not set any profile property. In this DNN forum you can finf how to resolve it. In my case in didnt' work. After try several alternatives I have fixed setting the properties out of the profile and directly into the UserInfo properties:

Example in DNN 4.0.X:
objNewUserInfo.Profile.FirstName="Alex";

Example in DNN 4.3.X:
objNewUserInfo.Firstname="Alex";

With this solution now I can sign in my users in portal.

Shrinking the Log File in SQL Server 2005

2006-09-26T17:16:00.000+02:00

Sometimes we need to delete the log file as quickly as possible. This is not the best way but is the most simple. Only in 6 steps:
1 - Detach DataBase
2 - Rename Log file or remove if tou are completely sure.
3 - Attach the database. You have to select the mdf file of the database.
4 - If you have deleted or renamed the log file tou will see an error "Not found" in the log file of the attached database.
5 - Select the log file with the error and click on "Remove"
6 - Click on "OK"

Now you have the same database without the large log file. Automatically SQL Server creates another file with minimum size and you can delete the file.

Use this method only to shrink database files without imprtance (development or test DB).

DotNetNuke, HttpContext & Scheduler

2006-06-11T14:35:00.000+02:00

This post resolves an issue with the HttpContext in a scheduled task. I had created a function that deleted the users from a portal. The problem was that I could not invoke to UserController because the application crash throwing an “Object reference not set to an instance of an object” Exception.

The reason is the invocation to UserController needs to get the HttpContext and it does not exist during the execution of a scheduler task. The solution consists is create an HttpContext and use it. In order to do I get the code from this post and translate to C#.

public class SchedulerHttpContext

{

private static string appPhysicalDir;

public static void setHttpContextWithSimulatedRequest()

{

string appVirtualDir = "/";

if (appPhysicalDir == null)

{

if (Thread.GetDomain().GetData(".appPath") != null)

{

appPhysicalDir = Thread.GetDomain().GetData(".appPath").ToString();

}

else

{

throw new Exception("Error 1: CRASH!");

}

if (appPhysicalDir.Length == 0)

{

if (Thread.GetDomain().GetData(".appPath") != null)

{

appPhysicalDir = Thread.GetDomain().GetData(".appPath").ToString();

}

else

{

throw new Exception("Error 2: CRASH!");

}

Thread.GetDomain().SetData(".appPath", null);

string page = ((string)(System.Web.HttpRuntime.AppDomainAppVirtualPath + "/default.aspx")).TrimStart("/".ToCharArray());

string query = "";

StringWriter output = new StringWriter();

SimpleWorkerRequest workerRequest = new SimpleWorkerRequest(appVirtualDir, appPhysicalDir, page, query, output);

HttpContext.Current = new HttpContext(workerRequest);

}

When I need to retrieve the user information I only have to invoke to SchedulerHttpContext.setHttpContextWithSimulatedRequest() at the beginning. Here you can see an example of a SchedulerClient:

public class CleanUsers : DotNetNuke.Services.Scheduling.SchedulerClient

{

public CleanUsers(DotNetNuke.Services.Scheduling.ScheduleHistoryItem objScheduleHistoryItem)

: base()

{

this.ScheduleHistoryItem = objScheduleHistoryItem;

}

public override void DoWork()

{

this.Progressing();

this.ScheduleHistoryItem.AddLogNote("Begin Task!");

SchedulerHttpContext.setHttpContextWithSimulatedRequest();

soSomething(); //doSomething can call to UserController methods

this.ScheduleHistoryItem.AddLogNote("Finished Task");

this.ScheduleHistoryItem.Succeeded = true;

}

Scheduled Task in DotNetNuke 4.0

2006-06-10T23:06:00.000+02:00

DotNetNuke offers the possibility of schedule some tasks. In this document you will get the instructions to create a scheduled task. This is valid for .NET framework 1.1. The problem is that we need to specify where the assembly that contains the scheduled task is, and the compilation model in ASP.NET 2.0 compiles our classes dynamically and we cannot know what the assembly that contains the class is.

In this post of Shaun Walker we can get a solution. He proposes to publish our web site in order to get the assemblies of our portal. This solution is a good solution when you need to deploy the website, but when you are developing the scheduled tasks you have to publish all website to get the assembly. This is a waste of time and it is not necessary. We can generate the assembly from the command line in a few seconds. These are the steps:

Create a SchedulerClient task. The class in the above document can be used as example.
Save the file as “Scheduler.cs” for example.
Compile the assembly from command line. If you are using VS 2005 you can do it from “Visual Studio 2005 Command Prompt” inside “Visual Studio Tools”. A valid command might be:
csc /target:library /out:Scheduler.dll /r:.\ReferenceAssembly.dll,
.\DotNetNuke.dll /recurse:Scheduler.cs
Copy the generated assembly (Scheduler.dll) in the bin directory of the DotNetNuke portal.
At this point you can follow the instructions in the document to configure the scheduled task.

Hola a tod@s!

2006-05-01T13:15:00.000+02:00

Nace "Experiencias .NET", un blog destinado a compartir todo aquello que crea interesante en el desarrollo de software en .NET 2.0.