How to play system sounds in C#

.NET Framework allows playing system sounds using a simple code:

SystemSounds.[Type].Play(); 
But the SystemSounds class supports only 5 types of sound notifications: Asterisk, Beep, Exclamation, Hand, Question.

There is no easy way to play other standard sounds like LowBatteryAlarm, DeviceConnect, DeviceDisconnect, MailBeep, and others from the Windows Sound Scheme.

We in BgRnD are using following function in our C# projects:

public void PlaySystemSound(string RegistryName)
{
    string fileName = "";

    RegistryKey key = Registry.CurrentUser.OpenSubKey(String.Format(@"AppEvents\Schemes\Apps\.Default\{0}\.Current", RegistryName), false);
    try
    {
        fileName = (string)key.GetValue("", fileName);
    }
    finally
    {
        key.Close();
    }

    if (!File.Exists(fileName)) return;

    SoundPlayer player = new SoundPlayer(fileName);
    try
    {
        player.Play();
    }
    finally
    {
        player.Dispose();
    }
}

The function plays the sound resource specified by the RegistryName parameter. The set of possible names you can find in the System Registry at HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default path.

Windows Sounds in the System Registry
Screenshot of Registry Editor to understand where to take Registry Names of system sounds.

You can freely use (copy and paste) this function into any of your projects.

If you still have any programming questions about playing the Windows sound notifications, feel free to ask.

Great tool to generate WMI queries

If you are planning to work with System.Management Namespace in the .NET framework, especially with ManagementObjectSearcher, ManagementObjectCollection, and ManagementObject classes, to perform different Windows Management Instrumentation (WMI) queries, take a look on WMI Code Creator tool by Microsoft.

Without this free utility, you'll spending lots of time to test your WMI queries via console or other debugging methodology.

Using the WMI Query Builder you can browse WMI namespaces, execute methods and receive WMI events. Also you can automatically generate a working source code to perform WMI queries, either C# or Visual Basic.

Moreover, you can modify and run these management scripts by pressing a single button! Visual Studio is not required for that 🙂

Power of Backward Loops

Loops aka cycles (while, for, do until, etc) are common in programming. Actually they are a language level implementation of the iterator pattern.

Those who learned programming in the college/university, remember lots of tasks for sorting an array or traverse a double-linked list in both directions. But in practice, very few people apply the backward loops.

There are a number of tasks where the reverse iteration automatically solves a bunch of problems, for example:

If you need to release all elements of array/collection/list, it is much easier to start from the end and delete the last element each time, rather then go from the beginning, save the length of the container, make the reference for every deleting object, and so on.

Compare this:

var len = someCollection.length();
for (i = 0, i < len, i++) {
    var element = someCollection[i];
    someCollection.delete(i);
    delete element;
}

with that:

var i = someCollection.length();
while (i--) {
    delete someCollection[i];
}

So the backward loop is not only for students, the backward traverse rules in many cases 🙂

Avoid same IDs for HTML elements

Many back-end developers don't care about clearance of HTML code. They think it is a front-end developers job...

Yes, but no 🙂 Developers should create a bulletproof code on both sides.

Very often, calling the PHP code, that generates some HTML template, for the second time creates two sets of HTML elements with the same IDs. This is wrong!

Here is a workaround to avoid same IDs for HTML elements using a global variable:

<?php
global $some_global_variable;
if (isset($some_global_variable)) $some_global_variable += 1; else $some_global_variable = 0;   

$form_id = '';
if ($some_global_variable > 0) $form_id = $some_global_variable;
?>

This is an example of HTML template for this hack:

<form role="search" method="get" id="searchForm<?php echo $form_id ?>" class="searchForm" action="/search/">
    <input type="text" id="searchText<?php echo $form_id ?>" name="search" value="" />
    <input type="submit" id="searchButton<?php echo $form_id ?>" value="" />
</form>

Try to be a good programmer every-time and everywhere!

Print any PHP variable easily

PHP developers often need to print value of different variables directly to the HTML code. But very often PHP variable is out of the current scope, so the echo(); function doesn't help. This PHP function prints any global (or external scope) variable by its name:

function print_var($var = 'domain', $url = '')
{
  global $$var, $$$var;
  if ($url != '')
    echo("<a href=\"$url\">${$var}</a>");
  else
    echo(${$var});
}

If you pass some URL as a second parameter you'll get a clickable link:

<?php print_var('page') ?>
<?php print_var('domain', '/') ?>
<?php print_var('software', '/download/') ?>
<?php print_var('site', 'http://www.site.com') ?>

We hope this PHP hack will be useful for everybody 🙂

States List for USA and Canada

Same to the countries list we are publishing the list of USA and Canadian states.

States list

Hint: Click on list, press Ctrl+A to select all, Ctrl+C to copy the list.

ISO 3166 Country Names

Every time programmers create the user panel in some program or website they have to search for a list of countries for dropdown or listview control. It is annoying...

So we've decided to palace such list in a public place. This is ISO 3166 Country Name list. You can freely use it in own projects.

Country Names

Hint: Click on list, press Ctrl+A to select all, Ctrl+C to copy the list.