WPF BackgroundWorker

BackgroundWorker code snippet for fun and profit:

var worker = new BackgroundWorker();
worker.DoWork += DoStuffOnBackgroundThread;
worker.RunWorkerCompleted += StuffOnBackgroundThreadCompleted;
worker.RunWorkerAsync(spaceId);

public void DoStuffOnBackgroundThread(object sender, DoWorkEventArgs e)
{
 var sampleParameterObject = ((string)e.Argument);
 //do work here
 e.Result = myResultObject;
}

public void StuffOnBackgroundThreadCompleted(object sender, RunWorkerCompletedEventArgs e)
{
  if (e.Result != null && e.Result is MyResultType)
  {
   //do stuff with result here
  }
}

WPF Link Listing for 3-19-2010

Lot’s of MIX10 related news this week.  But here are some WPF links, not related to MIX, from this week:

• Bea Stollnitz – Advanced Features for Line-of-Business Applications in Sliverlight and WPF Bea Stollnitz always has great content!
• How to: Create an advanced SketchFlow Prototype Kukas Zdechovan walks through using SketchFlow features of Expression Blend.
• Custom Layout in WPF Short article walking through creating custom layouts in WPF.
• How To Debug WPF Binding Another tool / strategy for debugging databinding in WPF.

WPF Link Listing for 3-12-2010

WPF Related links for 3-12-2010

• Silverlight TV 13: MVVM Light Toolkit Laurent Bugnion discusses MVVM with Channel 9
• WPF Patterns An older article, but still good content about using the MVVM pattern in WPF
• The Book of WPF Pete talks about Microsoft’s “Book of WPF”  ( The app I’ve worked on the last 2 years is listed on page 1 ) 
• ScrollBar control template in WPF Article walking through the steps of customizing a WPF scrollbar

WPF Link Listing for 3-11-2010

Below is a listing of interesting WPF links I’ve come across recently:

• The Essential WPF/Silverlight/XNA Developer and Designer Toolbox Pete Brown lists a collection of tools he’s used or the community does for developing great apps.
• How to Get Started in WPF or Silverlight: A Learning Path for New Developers Pete Brown provides advice on how to get started with WPF or Silverlight development.
• Request for Feedback (WPF VNext) Letster talks about the value of providing feedback for consideration for the next version of WPF.
• WPF Circular Progress Indicator Michael Detras walks through creating a Circular Progress Indicator in WPF.
• Enable MultiSelect in WPF ListView Leung Yat Chun shows how to support selection by dragging in a ListView in this CodeProject article.
• Good practice to use Dispatcher in WPF background thread Eric De Carufel walks through some extension methods he’s created for using Dispatcher in WPF.
• WPF NotifyIcon Philipp Sumi shows a cool NotifyIcon control he’s created
• WPF Performance and .NET Framework Client Profile A very good and technical article on optimizing WPF applications for Remote Desktop.

.NET Reflection

Wikipedia describes reflection as “The process by which a computer program can observe and modify its own structure and behavior.”  That’s a fairly generic definition and one that encapsulates a lot of different variations.  My understanding of reflection with respect to C# programming has always been the general idea of being able to dynamically run different chunks of code at runtime based on ‘data’.   

Meta-Information: “stores information such as the name of the contained methods, the name of the class, the name of the parent classes, and/or what the compound statement is supposed to do.  Using this information, as an object is consumed (processed), it can be reflected upon to find out the operations that it supports”

Ok, so we know that metadata or ‘meta-information’ is an important piece of the reflective programming concept.  meta-data is the ‘data’ used to make decisions about which code to run.

The following terms help me with my overall understanding of reflection and its use within the .NET framework…

Reflection: The ability to discover the overall makeup of a type (e.g. class, interface, structure, enumeration, etc.) at runtime.

Dynamic Loading: loading an assembly into memory programmatically at runtime. (think Assembly.Load or Assembly.LoadFrom)

Late Binding: The ability to create objects and invoke their members at runtime without compile time knowledge.  (think myAssembly.CreateInstance())

Attributes: Allows a developer to mark their code base with bits of custom metadata.  Attributes meaningless unless another piece of software finds and uses them via reflection

(Example real world usage – allowing a product to be extensible through the use of third-party plugins.  The extensible application defines an interface for the 3rd party plugins to implement and then these plugins can be dynamically loaded via reflection and late binding by the extensible application at runtime)

windbg notes for quick reference

attach to process

.load SOS (assumes dll is in debug tools folder)

.sympath SRV*c:\symbols*http://msdl.microsoft.com/download/symbols

debug -> break

!dumpheap -stat

!dumpheap -type Microsoft.Practices.EnterpriseLibrary.Caching

!dumpheap -mt <methodtable>   (Method Table)

!do <address>   (dump object)

!objsize <address>  (object size)

!dumpheap -stat -min 85000 (everything larget than 85000 == stuff on LOH)

!eeheap -gc  (managed heap size)

Configure EnterpriseLibrary Cache without app.config file

The basic approach to configuring the EnterpriseLibrary Cache application block from code, without using an app.config file.

private void TestCacheConfiguration()
{
 CacheManagerFactory cacheFactory = new CacheManagerFactory(GenerateConfiguration());
 cache = cacheFactory.Create(“Sample Cache Manager”);
}

private static DictionaryConfigurationSource GenerateConfiguration()
{
 DictionaryConfigurationSource sections = new DictionaryConfigurationSource();
 sections.Add(CacheManagerSettings.SectionName, GenerateDefaultCacheManagerSettings());
 return sections;
}

private static CacheManagerSettings GenerateDefaultCacheManagerSettings()
{
 CacheManagerSettings settings = new CacheManagerSettings();
 settings.BackingStores.Add(new CacheStorageData(“inMemory”, typeof(NullBackingStore)));
 settings.CacheManagers.Add(
  new CacheManagerData(“Smart Alert Cache Manager”,
   10000,
   1000,
   100,
   ”inMemory”));
 return settings;
}

What SQL Server Edition you are running?

Q.  How do you determine if you are running Standard, Enterprise, Developer, etc. edition of SQL Server?

A.  select SERVERPROPERTY(‘productversion’), SERVERPROPERTY(‘productlevel’), SERVERPROPERTY(‘Edition’)

No Visual Studio template information found.

I started getting this error in my Visual Studio IDE today: “No Visual Studio template information found.”

 

If we take a look in the event log we see additional detail on how to address the problem:

Open a command prompt to the location of devenv.exe and run the command: “devenv.exe /installvstemplates”

We are back in business!

The only outstanding question: why did this happen in the first place?