This snippet will show you how to get the currently logged in user on windows.
System.Security.Principal.WindowsIdentity identity =
System.Security.Principal.WindowsIdentity.GetCurrent();

Console.WriteLine(identity.Name);

To get width and height of an image we can use System.Drawing.Image class. This code snippet shows how to retrieve width and height of an image.

string filePath = @"c:\deepak\MeeGo.jpg";
Image img = Image.FromFile(filePath);
 
Console.WriteLine(string.Format("Height: {0}",img.Size.Height));
 
Console.WriteLine(string.Format("Width: {0}",img.Size.Width));

Windows Registry Size can be retrieved using WMI objects. This code snippet shows you how to get current size and maximum size for Windows registry.
ManagementObjectSearcher mgmtObjects =
new ManagementObjectSearcher("Select * from Win32_Registry");

foreach (var item in mgmtObjects.Get())
{
Console.WriteLine(string.Format("Current Size: {0}MB", item["CurrentSize"]));
Console.WriteLine(string.Format("Maximum Size: {0}MB", item["MaximumSize"]));
}

 
The output.

In .Net Framework reversing array elements can be done by using Reverse method on Array type. This code snippet shows you how this method can be used to reverse an array.
// Declare an array with 10 elements
int[] numbers = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

// Output [...]

To convert a Hexadecimal to a number we can use an overload of Convert.ToInt32 method.

Using the overload I can convert for example hex string “BB” to a number.
int number = Convert.ToInt32("BB", 16);

And the number variable gets assigned value of 187.

To get free disk space for all physical drives on a machine we can use xp_fixeddrives extended stored procedure. An interesting this about this procedure is that it is not documented in books online.
EXEC xp_fixeddrives

Here is output on my machine.

You’ve got to love sys views in SQL Server. While learning about performance tuning on SQL Server 2008 I wanted to get a list of all Indexes on my database and the answer was as simple as it can be. Here i a statement which can be used to get a list of all indexes [...]

This is where reflection comes in handy. The following code snippet shows you how to get the name of executing assembly.
string assemblyName;
assemblyName = System.Reflection.Assembly.GetExecutingAssembly().FullName;
Console.WriteLine(assemblyName);

 
Output for the above code returns the fully qualified name as shown below

 
To just get the Assembly name we can use this snippet.
string assemblyName;
assemblyName = System.Reflection.Assembly.GetExecutingAssembly().GetName().Name;
Console.WriteLine(assemblyName);

Here is the output.

This snippet shows you how to get information about all CD / DVD drives on your machine using WMI and C#. To run the code you need to add reference to System.Management.
ManagementObjectSearcher mgmtObjects =
new ManagementObjectSearcher("Select * from Win32_CDROMDrive");

foreach (var item in mgmtObjects.Get())
{
Console.WriteLine("Drive Letter – \t" + item["Drive"]);
Console.WriteLine("Name – [...]

This query returns the last row from Sales.Customer table in Adventure Works database. I am using LINQPad to write and execute my query.
(from c in Customers
select c)
.OrderByDescending(x=> x.CustomerID).First()
 
Here is the result as displayed in LINQPad
 

To do this you will need to add references to System.Drawing and System.Windows.Forms. Make sure that you have following using statements:
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

 
In your method add this code. It will take a screenshot of your primary screen and save it to a file.
Bitmap bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
[...]

There are times when we want to return empty strings for column(s) which have NULL values. T-SQL makes this easy with ISNULL function. Two parameters for this function are:

The column in question
Replacement value

 
Here is an example query for Customers table in Northwind database. This query will select Region column [...]