Por Paulo Morgado O novo paradigma de aplicações com ligação à nuvem leva a que a latência das comunicações seja maior do que aplicações totalmente locais. Para auxiliar o desenvolvimento deste novo paradigma, a última versão do C# 5.0 faz com que programação assíncrona pareça tão fácil como a programação síncrona

1. NOME DA APRESENTAÇÃO
Nome (Nick no Fórum)
25 DE MAIO @MICROSOFT
What’s New In C# 5.0
Paulo Morgado (paulo.morgado)

2. Paulo Morgado
CodePlex
Revista
PROGRAMAR

3. A Language For Each Generation
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4. The Evolution Of C#
# 4
C# 1.0 C# 2.0 C# 3.0 C# 4.0 C# 5.0
Managed Generics LINQ Dynamic Async

5. The Evolution Of C#
# 5
C# 1.0 C# 2.0 C# 3.0 C# 4.0 C# 5.0
Managed Generics LINQ Dynamic Async
please wait for the next slide
clicking won’t make it come any faster

6. DEMO
Synchronous UI Application

7. Introducing Async

8. Introducing Async - Yesterday
# 8
Click
void LoadImage()
{
// ...
LoadLocalData(...);
// ...
}
void Button_Click(...)
{
LoadImage();
UpdateView();
}
Click
Messagepump

9. Introducing Async - Today
# 9
Click
void LoadImage()
{
// ...
DownloadRemoteData(...);
// ...
}
void Button_Click(...)
{
LoadImage();
UpdateView();
}
Click
Messagepump

10. DEMO
Add the async & await keywords

11. Introducing Async
async void Button_Click(...)
{
await LoadImageAsync();
UpdateView();
}
async Task LoadImageAsync()
{
// ...
await DownloadRemoteDataAsync(...);
// ...
}
Messagepump
void LoadImage()
{
// ...
DownloadRemoteData(...);
// ...
}
void Button_Click(...)
{
LoadImage();
UpdateView();
}
Click

12. Introducing Async
# 12
Click
async Task LoadImageAsync()
{
// ...
await DownloadRemoteDataAsync(...);
// ...
}
async void Button_Click(...)
{
await LoadImageAsync();
UpdateView();
}
Click
Messagepump
Task ...
DownloadRemoteDataAsync
Task ...
LoadImageAsync
Download
LoadImage

13. DEMO
Async UI app: re-entrancy and deadlock

14. DEMO
Async with cancelation

15. DEMO
Async console app

16. DEMO
Async unit tests

17. Source Code Caller ID

18. Source Code Caller ID
• CallerFilePathAttribute
• Allows you to obtain the full path of the source file that
contains the caller. This is the file path at the time of
compile.
• http://msdn.microsoft.com/library/system.runtime.compilerservices.callerfilepathattribute.aspx
• CallerLineNumberAttribute
• Allows you to obtain the line number in the source file at
which the method is called.
• http://msdn.microsoft.com/library/system.runtime.compilerservices.callerlinenumberattribute.aspx
• CallerMemberNameAttribute
• Allows you to obtain the method or property name of the
caller to the method.
• http://msdn.microsoft.com/library/system.runtime.compilerservices.callermembernameattribute.aspx
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19. Source Code Caller ID - Examples
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static void TraceMessage(
string message,
[CallerMemberName] string memberName = "",
[CallerFilePath] string sourceFilePath = "",
[CallerLineNumber] int sourceLineNumber = 0)
{
Trace.WriteLine(
string.Format(
"{0} at {1} in {2}:line {3}",
message,
memberName,
sourceFilePath,
sourceLineNumber));
}

20. Source Code Caller ID - Examples
# 20
private string field;
public string Property
{
get { return this.field; }
set
{
if (this.field != value)
{
this.field = value;
this.NotifyPropertyChanged();
}
}
}
protected void NotifyPropertyChanged([CallerMemberName] string propertyName =
"")
{
// …
}

21. Breaking Changes

22. Breaking Changes
• You can use the iteration variable of a foreach statement in a lambda
expression that’s contained in the body of the loop.
• You can use the iteration variable of a foreach statement in a LINQ
expression that’s contained in the body of the loop.
• Overload resolution has been improved for calls that use named arguments
to access methods that contain params parameters.
• Overload resolution is improved for calls where the algorithm must choose
between a Func<object> parameter and a Func parameter that has a
different type parameter (e.g., string or int?) for a Func<dynamic>
argument.
• Side effects from named and positional arguments in a method call now
occur from left to right in the argument list.
http://msdn.microsoft.com/library/hh678682(v=vs.110).aspx
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23. Resources

24. Resources
• C# Reference
• http://msdn.microsoft.com/library/618ayhy6.aspx
• Breaking Changes in C# 5.0
• http://msdn.microsoft.com/library/hh678682(v=vs.110).aspx
• .NET Framework 4.5
• http://msdn.microsoft.com/library/vstudio/w0x726c2(v=vs.110).aspx
• Task Parallel Library (TPL)
• http://msdn.microsoft.com/library/vstudio/dd460717.aspx
• Asynchronous Programming with Async and Await (C#
and Visual Basic)
• http://msdn.microsoft.com/library/hh191443.aspx
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25. Resources
• Task-based Asynchronous Pattern
• http://msdn.microsoft.com/library/hh191443.aspx
• Task.Run vs Task.Factory.StartNew
• http://blogs.msdn.com/b/pfxteam/archive/2011/10/24/10229468.aspx
• An Async Premier
• http://msdn.microsoft.com/vstudio/jj573641.aspx
• Eduasync by Jon Skeet
• http://msmvps.com/blogs/jon_skeet/archive/tags/Eduasync/default.aspx
• Eric Lippert's Blog
• http://ericlippert.com/
• http://blogs.msdn.com/b/ericlippert/archive/tags/c_2300_+5-0/async/
# 25

26. Resources
• Lucian Wischik's Blog
• http://blogs.msdn.com/b/lucian/archive/tags/async/
• Parallel Programming Team Blog
• http://blogs.msdn.com/b/pfxteam/archive/tags/async/
• What’s new in C#5? – Red Gate
• http://www.youtube.com/watch?v=z7nry67oeKc
• Novidades Do C# 5.0 – Comunidade NetPonto
• http://www.youtube.com/watch?v=7Tl6CHf86z4
• Sample Code
• http://code.msdn.microsoft.com/C-50-AsyncAwait-Demo-
Code-334679a5
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27. Resources
• Paulo Morgado
• @PauloMorgado
• http://PauloMorgado.NET/
• http://mvp.support.microsoft.com/profile/Paulo.Morgado
• http://msmvps.com/blogs/paulomorgado/
• http://weblogs.asp.net/paulomorgado/
• http://pontonetpt.org/blogs/paulomorgado/
• http://www.codeproject.com/Members/PauloMorgado
• http://code.msdn.microsoft.com/site/search?f%5B0%5D.Type
=User&f%5B0%5D.Value=Paulo%20Morgado
• http://www.codeplex.com/UserAccount/UserProfile.aspx?Us
erName=PauloMorgado
• http://www.slideshare.net/PauloJorgeMorgado
# 27

28. Q&A

29. Patrocinador Gold
Patrocinadores Silver

30. Media Partners

31. NOME DA APRESENTAÇÃO
Nome (Nick no Fórum)
25 DE MAIO @MICROSOFT
Thank You!
Paulo Morgado (paulo.morgado)