Posts filed under 'Programming'
Microsoft Office 2007 comes with 3 colour (color) schemes.
Users can easily change it but when you deploy an Access application under the Runtime your users have no way to set the colour scheme as the application’s options are not available.
Luckily for us, Office 2007 stores the global colour scheme setting in the registry under:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Common\Theme
The values being stored under that key are:
- Blue scheme
- Silver scheme
- Black scheme
With this information, we can easily both read and set the colour scheme.
The only caveat is that I could not find a way to notify Access to reload the setting automatically once it is changed, so users will have to restart the application before the change becomes active.
A small price to pay but if anyone has a better idea, please let me know.
To write the new value to the registry I use a set of WIN 32 APIs that are more flexible than the default ones provided in VBA.
You can download the sample database as it contains all necessary files, including the definition for the Win32 API functions.
Download the ColorScheme.zip (31KB) containing the ACCDB database.
The sample also contains some code to restart the database. It will probably be the subject of a next post.
Improvements/uses:
- Find a way for Access to reload the settings without having to restart the application.
- Use the knowledge about the current scheme to change the other colour settings in the application (or even adapt the form’s theme).
References:
May 3rd, 2008
Rob Cooper, of the Microsoft Access Team made an interesting post and a follow-up on how to add a transparent layer that cover the screen to focus the attention of the user to a login form or other important popup window.
The trick is to use some WIN 32 API calls to modify the transparency of a standard MS Access form made to cover the screen.
The effect is quite neat and I thought I would try it and make a sample database for others to tinker with it.
My version allows you to chose between covering the whole screen or just the main Access window and it will test if it’s running under a Remote Desktop Terminal and disable the layer in that case.
Update 07MAY2008
Following Rob’s improvements I made another sample database that incorporates his code with a few improvements:
- I added the
LightBoxForm.LayerToFullScreen property so users can choose explicitly how they want the layer to be shown.
- I moved the code to hide the layer into a Hide() sub so you can just show/hide the layer using
LightboxForm.Show and LightboxForm.Hide.
- I changed the Form’s
Resize event code in the LightBoxForm class to avoid flickering: resizing the form within its Resize event actually trigger the Resize event again a second time which causes flickering.
I simply modified the code to make the form totally transparent (opacity of 0) the first time the event is fired and assign it the expected opacity when the event handler in re-entered.
Samples
There are now 2 sample databases. Ech zip contains a Microsoft Access 2007 ACCDB file and its conversion to Access 20001 and Access 2002-2003 MDB but please note that I have not been been able to test those in older version of Access and that form transparency doesn’t work in Operating Systems older than Windows 2000.
Download TransparentLayer02b.zip (138KB), recommended version
(improved, more flexible version, based on Rob’s updated article).
Download TransparentLayer01b.zip (122KB), original version
(simple code, based Rob’s original article).
Troubleshooting
- If you are getting security warnings: make sure that you open the database from a Trusted Location or you will receive a security prompt.
If you don’t know how to do that, check these steps.
- If the layer appears on top of the login form instead of behind: make sure that the top-most form has ist
Modal properties set to Yes and the frmLightBox form has its modal property set to No.
If you improve on it, please let me know and I’ll post it here for all to find.
May 1st, 2008
Decoupling the User Interface from the underlying code has been one of the holy grails of application development.
Layers of indirection and new patterns have been invented over time to try to separate what the user does from the back-end data. It’s been a long and difficult journey but WPF is the last attempt at completely separating the user interface from the gut of an application, leaving graphic designer do what they do best and programmers do what they do best.
I think this disconnect has actually hindered the adoption of WPF to a great extent.
I also believe that Silverlight, while showing great promises, is going to take a long time to get off the ground.
Good graphic designers who work on User Interfaces are too few and far between, and large organisations will take time to get staff with a sufficient level of expertise to be useful in developing meaningful WPF/Silverlight applications.
Until now, the bulk of the development effort was done by developers. Most ISV only have developers onboard.
As far as I can tell, it seems that main reason behind this slow adoption is that WPF/Silverlight has only been noticed by developers and they don’t know what to make with it.
WPF/Silverlight are not really developer-friendly: the development infrastructure is there but we’re left with a blank canvas and nothing to drag and drop onto it.
There will be a great gap, probably lasting a few years, before there are enough experiments in these new user interfaces that some useful lowest common denominator can be exploited by non-designers.
We’ll have to wait for tool vendors to provide the bulk of user interface blocks and for a few new patterns to appear before all the designer-challenged developers like me can make decent interfaces without requiring a professional graphic designer in their midst.
In the mean time, we’ll probably have useless, but pretty, applications, some useful, but ugly ones and a lot of people scratching their head trying to couple the designers and the developers in a working relationship.
February 10th, 2008
Microsoft SQL Server comes in many editions, ranging from completely free to use and distribute to versions costing tens of thousands of dollars.
For small businesses, or when you can live with the limits imposed, the Express edition is one option to consider.
Here are some reasons why SQL Server Express may be a good choice:
You’re upsizing an Access database
SQL Server is the natural extension of upsizing an existing Access database. It work automagically with minimum effort providing that you followed some simple good-design rules from the start.
You’re future-proofing your needs
Because SQL Server comes in many flavours, you know you -or your customers- can upgrade to a more capable (albeit more expensive) version in the future if needed.
Very flexible
As usual with a lot of Microsoft development tools, SQL Server will happily let you shoot yourself in the foot by providing you with a fairly easy way to treat your database as a complete development platform.
It’s good in the sense that you have interesting tools and capabilities included in the server, and it’s bad for the exact same reasons.
I tend to prefer database servers to be just that: data repositories, and I’m not too fond of relying on specific, non-standard features of a particular database system, but what do I know.
Excellent out-of-the-box development support
Deep integration with .Net and Visual Studio, without any effort, Microsoft saw to that of course.
In some cases, such as LINQ to SQL, it’s almost the only real choice, although the other database vendors are working hard at the necessary providers, so that lead should be short-lived.
There is something to be said about developer productivity: you have to give credit to Microsoft for making their tools well integrated and usable from each-other. What it means is that for small developer shops there is much to gain in surrendering to this “ease of the default”.
Of course, it’s a double-edged sword, but having a complete development infrastructure work out of the box is certainly a big help, and if you don’t like it, you’re still free to chose something else.
Lots of tools
With SQL Server Advanced Services, you also get Server Management and Reporting Services. These are great tools made available for free.
The only missing one for SQL Server is the Reporting designer. While the reporting service means that you can use existing reports, only SQL Server Standard and Enterprise have it.
There is an option for developers though: the (nearly free) SQL Server Developer edition is in fact the same as SQL Server Enterprise, without the license to use in non-developer or tester environment. This means that as a developer, you can create and distribute your reports to be used by your customers who will be using SQL Server Express.
Did I mention it’s free?
All this is free, as in beer, not as in liberty though.
For commercial applications targeted at small businesses, SQL Server Express is a really good choice: you can distribute it without problem, the customer gets all the tools, can easily find outside support, and they can always migrate to a more beefy version if their needs grow, all that without having to depend on you.
So it sort of offers customers a kind of freedom that they wouldn’t have with other choices.
Of course you can get that with other database systems, although you have to be careful which Open Source one you choose: I recently decided not to use MySQL any longer for the simple reason that it’s too expensive and restrictive in a business environment, at least for the kind of work I do.
Why would you not want to use SQL Server Express?
You don’t want to depend on Microsoft
That can be a good reason enough sometimes. There is nothing preventing Microsoft from crippling SQL Server Express in the future to force users to move to a paying version early.
I suppose that whatever database system you use, even Open Source ones, there is always the possibility that the company supporting its development goes bankrupt, the Open Source projects goes dead or decides to go in a direction that doesn’t suit you..
It’s only supported on Microsoft OS
True, and that’s a good reason to chose something else.
There is a hidden cost in SQL Server Express: it needs to run on a Windows machine, and that’s not free, although SQL Server will work on older Windows 2000 machines and Windows XP which are arguably not expensive.
Your database needs will exceed SQL Server Express specifications
If you think any of your databases will grow beyond 4GB or that it will get busy and you need all the RAM and CPU you can get, then SQL Server Express is probably not for you as it will only use 1 CPU and 1GB of RAM at most.
If your needs go beyond that, then you’ll have to move to a paying version.
Upgrading can be expensive
It’s true that moving to the next cheapest upgrade of SQL Server Workgroup will cost you about US$700 for a 5 user license. The limits imposed on the database are much higher (2 processors, 3GB RAM and no size limit) but if you need more clients / or higher limits, then the expense will grow quite fast, and you’ll have to manage those hateful client access licenses.
Your needs are more modest
We haven’t talked here about single-file/single-user database systems.
These databases don’t user resident services and are usually meant for more limited needs, sometimes allowing only a single user to be connected.
The footprint of these non-server databases is a lot smaller, typically only requiring a single dll or a handful of files to be installed.
They are extremely useful for desktop application that do not really require multi-user support or advanced security features.
Here again, Microsoft offers SQL Server Compact, which, despite the name, doesn’t have much to do with the other SQL Server editions. This one is also free, but has a limited feature set and only allow single-user access as it is meant to be a lightweight database and works well in limited memory environments such as those found on mobile devices.
Of course, here again there is a lot of competition: Thunderbird, SQLite, MS Access and VistaDB (for embedding into .Net applications, not free) to name a few.
These are pretty good times when it comes to databases: we get more choices now than we ever had.
As usual, choosing a database as a back-end for your products isn’t easy: you need to consider cost, licensing, support and the future.
There isn’t a single database system that will meet everyone’s needs for all types of use, so choose carefully.
SQL Server Express is a very good contender in that market. It should not be dismissed out of hand because it’s from Microsoft, in the same way that PostgreSQL shouldn’t be dismissed because it’s Open Source.
Just use the tool that best answers your needs for your particular circumstances.
References:
January 30th, 2008
What does 04/05/01 mean to you?
Let’s make it easy: is that date in 2001 or 2004?
And if I write it like 04/05/2001, is it really better? are we in April or May?
And the answer is…
If you are from North America and a handful other countries 04/05/01 would mean 5th of April 2001.
If you’re in Asia or some eastern countries, if could be 1st of May 2004.
For the rest of the world, it would look like 4th of May 2001.
We cannot ignore any longer the importance of writing dates in a format that is understandable by everyone.
Still too often, web sites -even big companies- with a global audience state dates in a format that is probably obvious where they live but not consistently so to everyone else.
Developers are sometimes guilty of this sin, as can be seen in the format chosen to specify dates in Microsoft Access SQL, which requires that hard-coded dates be formatted in the US rather than the more neutral ISO8601 format.
I wonder how many bugs that little egocentric feature caused in business applications that where developed by foreign coders…
I know it also happened to me at least once…
The worst thing is that when you write 04/05/06, you may very well have thought about the rest of the world and meant DD/MM/YY; alas, unless the context grants us some clarification or the actual date is unequivocal, there is sometimes no way for a lot of us to know for sure what you really meant.
We should ban the use of the short date format in communications that may be read by more than 3 people, in today’s world, that’s pretty much all communication.
Instead a simple format such as 05MAY2006 is clear an unequivocal: it’s easy to read and understand, regardless of where you live.
You’re free to add spaces, dashes, dots, comas or slashes to it if you want, you can use 2006MAY05 if you prefer or even MAY05,2006, whatever pleases you: it still remains readable.
The rule is simple:write the year in full and never write the month as a two-digit number, that’s reserved for the day
The point is that you, me and the rest of the world can read it and understand exactly what was meant; it’s an easy problem to solve.
Surely that means something to you?
References
December 15th, 2007
Next Posts
Previous Posts
