The document discusses various small features and techniques in .NET called "little wonders" that can improve code readability, maintainability, and performance. It provides examples of implicit typing, auto-properties, using blocks, static class modifiers, casts, string methods, object and path helpers, Stopwatch, TimeSpan factories, operators, initializers, and extension methods. The techniques allow writing more concise and clear code to handle common tasks like property declaration, exception handling, null checking, and LINQ queries.

1. James Michael Hare
2012 Visual C# MVP
Application Architect
Scottrade
August 3rd
, 2012
http://www.BlackRabbitCoder.net
Twitter: @BlkRabbitCoder

2. Me:
Blog: http://www.BlackRabbitCoder.net
Twitter: @BlkRabbitCoder
Information on Scottrade Careers:
http://jobs.scottrade.com
Twitter: @scottradejobs

3. What are “Little Wonders”?
The .NET Framework is full of “macro-sized”
goodness that can help make our coding lives easier
by automating common tasks.
But, the .NET Framework also has a lot of smaller
“micro-sized” tips and tricks that can improve code.
Many developers know of most of these, but it is
often surprising how many times newer developers
don’t.
These are just a few of those items, there are many
more.

4. How do they help?
Basically, by employing these small items at the right
time, you can increase application:
Readability – some of the wonders make code much
more concise and easy to read.
Maintainability – often goes hand and hand with
readability, by removing ambiguity of the code, it is
easier to maintain without introducing errors.
Performance – a few of the little wonders can even help
increase the performance of your code (depending on
usage).

5. The Little Wonders
Syntactical Sugar
Implicit Typing
Auto-Properties
using Blocks
static Class Modifier
Casts
as (TryCast)
String
Case-Insensitive Equals()
static IsNullOrEmpty()
static
IsNullOrWhitespace()
Object:
static Equals()
Path
BCL Class for Path Handling
Stopwatch
BCL Class for Timing
TimeSpan
static Factory Methods
Operators
Conditional
Null-Coalescing
Initializers
Object Initializers
Collection Initializers
Extension Methods
Defining Custom Extensions
LINQ Extension Methods

6. Implicit typing
So many times declarations and instantiations are
redundant:
C#:
VB:
Since declared type is same as instantiated type, can
use implicit typing:
C#:
VB:
Generally speaking, more readable since less
redundant typing.

7. Auto-Implemented Properties
Most properties simply get/set a backing field:

8. Auto-Implemented Properties
Manually creating these can make code more bloated.
Auto-Implemented properties take the pain out of
declaring simple properties:
Automatically creates a private, hidden backing field.
Automatically creates a getter that returns field.
Automatically creates a setter that assigns field.
VB allows you to assign auto-property inline.
C# allows you to have different accessibility for set and
get (i.e. you can create read-only properties).

9. Auto-Implemented Properties
C#:

10. Auto-Implemented Properties
VB:

11. Using using Blocks
When using an IDisposable instance, be careful how
you clean up:
What happens if exception is thrown before one or all
are disposed?

12. Using using Blocks
Fully protecting gets ugly fast…

13. Using using Block
Safer -- handles Dipose() even if exception.
Can stack multiple using declarations in C#.
Looks cleaner than multi-indenting.
C#:

14. Using using Block
VB doesn’t look quite as clean when “stacked”, but
still cleaner than the try/finally.
VB:

15. Static Class Modifier
Some utility classes contain only static methods:

16. Static Class Modifier
Classes with only static (Shared) methods and
properties shouldn’t be instantiated or inherited.
Could mark class sealed (NotInheritable) and
create private constructor:

17. Static Class Modifier
Instead, mark class static and will prevent
inheritance, instantiation, and instance members.
C#:
VB doesn’t have static modifier for classes:
 Modules are the VB.NET equivalent.

18. The as Cast (TryCast)
If you use is check followed by a cast, you are checking twice…
C#:
VB:
The as cast (TryCast in VB) lets you do a conditional cast if type
is convertible, or null if not.

19. The as Cast (TryCast)
C#:
VB:

20. Case-Insensitive String Equals
Sometimes you will see someone attempting to check
case-insensitive string equality by using ToUppper():
C#:
VB:
This creates a temp string that needs to be garbage
collected later.

21. Case-Insensitive String Equals
Instead of converting ToUpper(), use optional
argument for case-insensitivity:
C#:
VB:
Can also be applied to static String.Equals().

22. String Compare
Returns integer result of whether the first argument
is less, equal, or greater than the second argument.
Has optional parameter for case-insensitive.

23. Static String Empty Checks
Often time in code you will see something like:
C#:
VB:
Compound expressions are harder to read.
Can lead to buggy code if incorrectly coded or
inverted.
If string has whitespace, what then?

24. Static String Empty Checks
The System.String class has some static methods for
checking for null, empty, or whitespace only strings:
IsNullOrEmpty() – returns true if reference is null or
contains a completely empty string (zero Length).
IsNullOrWhiteSpace() – returns true if reference is
null, zero Length, or if all characters in string are
whitespace.
These static methods make the intent of the code
cleaner and eliminate need for compound expression.
Inverting the condition is also much more obvious.

25. Static String Empty Checks
C#:
VB:

26. Static Object Equals Check
What happens in the following if the LHS is null?
C#:
VB:
Equals() instance method can handle null RHS, but
not LHS.

27. Static Object Equals Check
You could check for null of LHS first, but gets ugly.
Use static (Shared) Equals() method instead:
C#:
VB:
Safer than using operator == for most types since ==
relies on an operator overload to exist.

28. The Path Class
Path has helper methods for parsing/combining
paths.

29. The Stopwatch Class
BCL class in System.Diagnostics.
Allows for much more precise timing than comparing
DateTime instances.
Contains basic methods for controlling Stopwatch:
Start() – marks starting time to now.
Stop() – marks ending time to now.
Reset() – resets start and end times.
Contains properties to query duration including:
ElapsedMilliseconds – long for milliseconds elapsed.
Elapsed – precicse elapsed time as a TimeSpan.

30. The Stopwatch Class
C#:
VB:

31. TimeSpan Factory Methods
How many times have you seen code like this and
wondered what the TimeSpan represents?
C#:
VB:
The constructors for TimeSpan are a bit ambiguous.

32. TimeSpan Factory Methods
TimeSpan has a series of static factory methods:
TimeSpan.FromDays(double days)
TimeSpan.FromHours(double hours)
TimeSpan.FromMinutes(double minutes)
TimeSpan.FromSeconds(double seconds)
TimeSpan.FromMilliseconds(double millis)
These methods can be used to create TimeSpans of
varying durations in a way that promotes better
readability.

33. TimeSpan Factory Methods
C#:
VB:

34. The Conditional Operator
Essentially a mini if-then-else operator.
Best used for small decisions that lead to a value
assignment or return.
If used simply, can make code more concise.
C#:
<bool-expression> ? <if-true> : <if-false>
VB:
If(<bool-expression>, <if-true>, <if-false>)

35. The Conditional Operator
C#:
VB:

36. The Null-Coalescing Operator
Allows concise substitution for null (Nothing) references.
C#:
<reference> ?? <null-substitute>
VB:
If(<reference>, <null-substitute>)
Equivalent to conditional operator checking for null/Nothing:
C#:
value ?? substitue
value != null ? value : substitute
VB:
If(value, substitue)
If(value IsNot Nothing, value, substitue)

37. The Null-Coalescing Operator
C#
VB:

38. Object Initializers
Many times, we create an object and then
immediately set a series of properties:
Lot of repetitive code especially if names are long:

39. Object Initializers
Of course, you could make it easier by providing
constructors, but you lose some readability:
Also, would need several constructor overloads or
acceptable default parameters.
Object initializers come in handy because they can be
used to initialize any public property or field.
Improves readability since tagged with property
name.

40. Object Initializers
C#:
VB:

41. Collection Initializers
Similarly, creating collections can be repetitive:
Especially if the type contained is non-trivial:

42. Collection Initializers
Can use collection initializer syntax to add multiple
items at time of collection construction:
C#:
VB:

43. Collection Initializers
Even works well in conjunction with object
initializers for initializing collections of complex
objects:
C#:
VB:

44. Collection Initializers
What is the difference between these?

45. Collection Initializers
Initializers preserve beforefieldinit modifier in the IL:
Gives small performance bump - without beforefieldinit
the CLR must check the class to see if static constructor
called before accessing any static member.

46. Extension Methods
If you develop a good piece of generic functionality
and want to attach it to an existing (sealed) type or
interface, you can create an Extension Method
Treated just like a true instance method, except can
be called off null (Nothing) reference, although this
is not recommended.
In C#, create a static class and static method with
this keyword marking the first argument.
In VB, create a Module and mark with
<Extension()> attribute.

47. Extension Methods
C#:

48. Extension Methods
VB:

49. Extension Methods
Can call just like regular instance methods:
Can be useful for adding behavior generically or to
interfaces.
Used to give most of the LINQ functionality to
IEnumerable.
Overuse can cause confusion and pollute IntelliSense.

50. LINQ
Too many times developers re-invent the wheel.
Say you have a list of Product such as:

51. LINQ
If you wanted all products with value > 100 grouped
by category, you could do something like…

52. LINQ
Or use the LINQ extensions methods:
Or LINQ expression syntax:
Either way, the algorithms are already written and
unit tested and ready to use.
Don’t reinvent the wheel.

53. Questions?Questions?