chris mylonas blog

A Father Who Creatively Captures His Kids (20 photos)

2011-05-12T14:37:00.000+03:00

Jason Lee, a known wedding photographer creatively capture his kids.

http://www.mymodernmet.com/profiles/blogs/a-father-who-creatively

WPF applications and CA2104 rule

2008-12-03T22:46:00.002+02:00

If you are using static fields such as:

public static class Constants

{

public static readonly FontFamily MyFontFamily = new FontFamily("Segoe UI");

}

with “{x:Static}” markup extensions such as:

FontFamily="{x:Static this:Constants.MyFontFamily }"

you will get the following warning:

CA2104 : Microsoft.Security : Remove the read-only designation from 'Constants.MyFontFamily' or change the field to one that is an immutable reference type. If the reference type 'FontFamily' is, in fact, immutable, exclude this message.

If you remove the “readonly” modifier you get a different warning:

CA2211 : Microsoft.Usage : Consider making 'Constants.MyFontFamily' non-public or a constant.

In order to solve the problem convert the field, to a property with get accessor only, such as:

public static FontFamily MyFontFamily

{

get

{

return new FontFamily("Segoe UI");

}

Cool way to show crashed plugins

2008-09-20T09:09:00.003+03:00

Google’s Chrome has a cool way to display crashed plugins such as Flash.

A sad puzzle piece icon!

Quick way to rename objects on WinForms with Visual Studio

2008-09-05T08:00:00.003+03:00

Here is a quick way to rename objects of windows forms:

Open the windows forms designer.
Open the Document Outline (View|Other Windows|Document Outline)
Select the objects using Document Outline and rename them using F2 (edit)

Better than renaming from Properties window?

Vista and Bluetooth Headsets

2008-09-05T08:00:00.001+03:00

I decide to pair my Nokia BH-208 Bluetooth headset with my Compaq NX8220 laptop (running Vista Business SP1) to watch some cool videos from mix conference. I open the headset, enable the wireless and Bluetooth device and try to pair the headset. BUT the headset is not list of devices. Why? I try to understand what is going on.

A quick search on the web provides the answer.

Windows Vista RTM doesn’t support Bluetooth headsets. They include the functionality in beta versions, but they removed in RTM versions. This also includes the SP1 release which is already installed in my laptop.

I am pissed off, and decide to found a solution.

I found that Microsoft release Windows Vista Feature Pack for Wireless for OEM vendors only, and not for general public, but the update can be found on the internet.
I download and installed it. Beware that feature pack requires SP1.
Download and install the Bluetooth device drivers from HP because headset is a Bluetooth Peripheral Device and Vista needs drivers for this.

After that the headset appears in the list of devices and paired successfully.

The next big thing: Offline Web Apps

2008-03-20T08:00:00.000+02:00

Read the news in a different way!

2008-03-13T09:00:00.000+02:00

Great blog for WPF Data Binding

2008-03-13T08:00:00.000+02:00

Beatriz Costa works in the Data Binding Test Team and has great information for data binding.

Wallpaper Generator

2007-12-13T17:33:00.000+02:00

A nice WPF application that creates a wallpaper based on a photo folder.

Download the application from here.

FlowDocument and multiple threads

2007-12-13T08:00:00.000+02:00

Recently, I try to use the FlowDocumentScrollViewer to display FlowDocument's. So I create WPF window application that creates and displays flow documents with FlowDocumentScrollViewer.

The refresh button clears the contents of the documentPanel, and creates and displays a random number of flow documents.

This works as expected and creates a random number of flow documents on window.
My next step is to make this work in asynchronous manner. How is that possible? Enter DispatcherObject and WPF Threading model.
The basic technique is to use the Dispatcher methods and delegates to do the heavy operations in a different thread.
To demonstrate this, I create a new "Refresh Async" button and modify the flow document creation to include a 5 sec Sleep.
The next step is to add the delegate and dispatcher calls. The refresh async button handler uses the Dispatcher to asynchronously call the GenerateAndShowFlowDocumentHandler method which creates and displays the flow document.

This also works fine.

The next step is to create the FlowDocument in a separete thread and use the main UI thread for UI update.

When I try this I get exceptions!.

To resolve this issue, I should serialize the FlowDocument as Memory stream since FlowDocument's seems that they can’t serialize themselves on different threads.
Add the following before passing the flow document.

And to the handler :

And it works great!!

The fastest Windows Vista notebook is a MacBook Pro !!!!

2007-12-06T10:18:00.000+02:00

Watch the Ad: http://www.apple.com/getamac/ads/

More on Vista's File Copy

2007-10-03T11:36:00.000+03:00

Guess how much time it will take to extract a zipped file of about 5MB to a disk using Vista's extract feature?

How to port SQL Server OPENXML to Oracle PL/SQL

2007-09-13T11:54:00.000+03:00

If you want to port code that contain OPENXML calls from SQL Server to Oracle, you will find that there is no such call. OPENXML works with sp_xml_preparedocument and xp_xml_removedocument calls to produce (among other things) a relational table based on XML document.

In my case, I use the XML document to pass an array of primary keys, use them as a filter for a table and join and return them.

For example suppose an application based on SQL Server TSQL has:

A table "BRANDS" contain a BRAND_ID (INT) and a TITLE (VARCHAR)

such as:

BRAND_ID TITLE

1 Nokia

2 Siemens

3 Other

4 IBM

5 HP

A stored procedure GET_BRAND_LIST as:

CREATE PROCEDURE dbo.GET_BRAND_LIST(@IDLIST NTEXT )

AS

DECLARE @hDoc int

EXEC sp_xml_preparedocument @hDoc OUTPUT, @IDLIST

SELECT BRAND_ID, TITLE FROM BRANDS

INNER JOIN OPENXML (@hDoc, '/s/k',2) WITH (I int) AS ResultSet

ON BRANDS.BRAND_ID = ResultSet.I

EXEC sp_xml_removedocument @hDoc

RETURN

GO

And an XML input similar to:

where:

s is the root element

k specifies a primary key and

I the value of the primary key

such as:

calling GET_BRAND_LIST will return the brands with BRAND_ID equal to 1, 3 and 4.

Here is how to do the same in Oracle:

Use CBLOB instead on NTEXT to pass the XML value.

Use XMLType instead on sp_xml_preparedocument and sp_xml_removedocument calls.

Use XMLSequence to convert and create a temporary table filled with the primary keys.

Use EXTRACT to get the primary key value to perform the Join.

The complete Oracle code:
PROCEDURE GET_BRAND_LIST (cur_OUT OUT T_CURSOR, pIDLIST CLOB)
IS
anXmlType XmlType;
V_CURSOR T_CURSOR;
BEGIN
anXmlType := XmlType(pIDLIST);
OPEN V_CURSOR FOR
SELECT BRANDS.BRAND_ID, BRANDS.TITLE
FROM BRANDS,
table(XMLSequence(extract(anXMLType, '/s/k/*'))) ResultSet
WHERE BRANDS.BRAND_ID = TO_NUMBER(EXTRACT(value(ResultSet), 'I/text()'));

cur_OUT := V_CURSOR;
END;

Vista and File Copy

2007-04-01T22:42:00.000+03:00

The Antikythera Mechanism Research Project

2006-05-30T17:27:00.000+03:00

The Antikythera Mechanism is an ancient astronomical computer built by the Greeks around 80 B.C. It was found on a shipwreck by sponge divers in 1900, and its exact function still eludes scholars to this day.

Game Innovation Database.

2006-05-22T10:05:00.000+03:00

Do you remember "Shadow of the Beast"? Lemmings? probably YES...If you are a fan of computer games.

Well, GIdb goal is to classify and record every innovation in the entire history of computer and videogames.

Five Years of Design

2006-05-17T19:38:00.000+03:00

Martin Fowler writes about the articles of the past five years of IEEE Software “Design” section, before passing the editing of the section to Rebecca Wirfs-Brock. This last article explains the basic Design Principles, the derived Best-Practices and their role in the software development process.

Thanks Martin.

Development (Print) magazines are disappearing…

2006-05-16T17:13:00.000+03:00

CMP Media has recently “merge” two of the most known software development magazines; Software Development and the C++ Users Journal (one of the last magazines dedicated to C/C+) into Dr. Dobbs magazine. Fortunately, I have an active subscription to Dr. Dobbs and I won’t lose any subscription fees.
Several years ago, CMP has also ceased the publication of the “legendary” BYTE magazine which makes me very angry (back in 1998) because a valuable source of information has been lost.

Obviously big publishing companies began to realize the importance of getting all the information directly from the provider using its blog, from a Usenet forum, or from a web site found be Google Search, and they make major efforts to create software development portals to replace the gap.

The difference is obvious.

A Brief Look at C++0x

2006-01-04T00:14:00.000+02:00

Bjarne offers a sneak peek at the next version of standard C++ ("C++0x") which should be complete by 2009.

Do you know Al-Khowarizmi?

2005-05-05T20:11:00.000+03:00

According to Knuth (you should know Knuth), the word "Algorithm" is derived from the name Al-khowarizmi, a ninth-century Persian mathematician.

Embrace change.

2005-01-13T07:00:00.000+02:00

Are you trying to learn new things constantly?
Do you embrace change in your life?

Computer History Museum

2005-01-05T07:15:00.000+02:00

On April 7 of 1969, Steve Crocker sends around a memo entitled ‘Request for Comments.’ This is the first of thousands of RFCs that document the design of the ARPANET and the Internet.

Architecture of the World Wide Web

2004-12-24T10:50:00.000+02:00

Computer Pioneer Bob Bemer Passes Away

2004-07-08T07:42:00.000+03:00

Who was Bob Bemer:
* the 'father or ASCII' character set.
* the 'grandfather' of COBOL.
* the inventor of ESCAPE and BACKSLASH sequences.
* the man behind the '8-bit' byte standardization.
* a pioneer in 3-D dynamic prespective.

Bob Bemer was awarded by IEEE Computer Society with the Computer Pioneer Award.

Do you remember this machines?

2004-06-07T15:50:00.000+03:00

The fundamental parts of software today, remains the same as LISA or NextStep software written 25 years ago, with a complete GUI metaphor, a true pre-emptive multitasking operating system, productivity applications an a true object oriented development environment.

Visual C++ 2005

2004-06-03T07:00:00.000+03:00

Microsoft Visual C++ returns as mainstream programming language with the next release of Visual Studio. Microsoft enhances the runtime libraries, the STL and adds language constructs for .NET compatibility.

OO in One Sentence

2004-05-20T12:04:00.000+03:00

Keep it DRY, Keep it Shy, and Tell the Other Guy..

Here is the original paper from Andy Hunt and Dave Thomas.

Operational - Reporting Databases

2004-05-19T20:00:00.000+03:00

Martin Fowler's - Reporting Database

The separation of reporting database from the operational database provides unique advantages such as: data from business logic (calculated), a de-normalized view of database (fewer joins), maintainability of operational database and runtime performance (fewer locks)

See also:
* Martin Fowler Bliki
* Reporting from Database

Favorite links

2004-05-17T10:32:00.000+03:00

Allen Bauer, Borland Delphi and C#Builder IDE Architect(http://homepages.borland.com/abauer/index.html)

Don Box's Spoutlet (http://www.gotdotnet.com/team/dbox/default.aspx)

Charlie Calvert (http://homepages.borland.com/ccalvert/index.htm)

Danny Thorpe, Delphi Compiler Architect (http://homepages.borland.com/dthorpe/blog/delphi/)

Steve Vinoski's Weblog (http://www.iona.com/blogs/vinoski/)

Hallmarks of a Good Design Review

2004-05-16T22:10:00.000+03:00

* The reviewers are looking for issues in the design not on the designer.

* The reviewers and the designer should have the right attitude.

* A design engineer should accept criticism of his ideas and proposals by the reviewers.

* Distribute related artifacts to all reviewers before the actual review.

The Principles of Lean Software Development

2004-05-16T10:19:00.000+03:00

Eliminate waste by removing anything that does not add value - Create teams of people with specific responsibilities to enhance value.

Amplify learning by increasing feedback – Create weekly to monthly, full cycle iterations.

Keep your options open – Share, Organize direct collaboration, Absorb changes, Refactor, Automate test.

Deliver Fast – Enable a smooth, rapid flow in response to customer needs.

Empower the Team – Train the team to design its own process and make commitments.

Conceptual and Perceived Integrity – Test early, test often, test exhaustively and use an automated test suite.

Welcome

2004-05-12T11:13:00.000+03:00

Welcome to my blog.
This site serves as a repository of my knowledge and a daily log.

I am a consultant and software engineer specialize in distributed systems, C++, OO analysis and design, relational and object databases, patterns, and software architectures. You can contact me at chris.mylonas@computer.org or chrisml@hol.gr.

Member of the IEEE Computer Society.