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Posted By:      Posted Date: August 28, 2010    Points: 0   Category :.NET Framework
Any realtime example for constructor...???

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new SelectList() :(

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System.Uri constructor. Bug or my misunderstanding?

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Custom Authenticate Attribute with Constructor (Dependency) Injection

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Error - No parameterless constructor defined for this object.

I am doing Music Store sample application.Here my code.StoreViewModel public class StoreManagerViewModel { public Album Album { get; set; } public SelectList Artists { get; set; } public SelectList Genres { get; set; } } StoreController public ActionResult Create() { var Artists = storeDB.Artists; var Genres = storeDB.Genres; StoreManagerViewModel model = new StoreManagerViewModel() { Album = new Album(), Artists = new SelectList(Artists, "ArtistId", "Name"), Genres = new SelectList(Genres, "GenreId", "Name") }; ViewData["Artists"] = model.Artists; ViewData["Genres"] = model.Genres; return View(model); } [HttpPost] public ActionResult Create(StoreManagerViewModel model) { try { if (ModelState.IsValid) { Album album = new Album() { Title = model.Album.Title, Price = model.Album.Price, ArtistId = Convert.ToInt32(model.Artists.SelectedValue), GenreId = Convert.ToInt32(model.Genres.SelectedValue),

WPF app never appears if showing a MessageBox during App constructor!?

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Why I get "Constructor supports only the 'Reset' action" on Add in ObservableDictionary with DataG


I replace ItemsSource in DataGrid by new ObservableDictionary (dataGridStatistic.ItemsSource = reportData; on Window_Loaded);.
Why I get "Constructor supports only the 'Reset' action"?

I have error "Constructor supports only the 'Reset' action" when




Private constructor


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If I attempt to new-up a custom class in my Workflow constructor:

_workflowInfo =  
                new WorkflowInfo(workflowProperties.OriginatorUser, workflowProperties.Item,  

... I receive the following error:

Error 1 Could not create activity of type '{Workflow}'. System.ArgumentNullException: Value cannot be null.
Parameter name: uriString
   at System.Uri..ctor(String uriString)
   at Microsoft.Shar

why always display " CssStyleCollection has no constructor function!!!"



   protected void GridView1_Row(object sender, GridViewRowEventArgs e)
        foreach (TableCell cel in e.Row.Cells)
            if (cel.Text.ToString() == "??")
                e.Row.BackColor = Color.FromName("#000084");
                e.Row.ForeColor = Color.White;
                CssStyleCollection mid = new CssStyleCollection();  // display complier error : CssStyleCollection has no constructor function!!!"     But Why????



ArgumentOutOfRangeException from default constructor of Hashtable



We have observed really seldom (not reproduceable) an exception from the default constructor of the Hashtable and wounder how this could happen. The application (WPF UI) uses:

- .Net Framework 3.5 SP1

- Microsoft Composite Application Guidance (October 2009)

- Microsoft Enterprise Library (October 2008)

- WPF Toolkit (June 2009)

- a couple of other libraries that we not yet loaded at the time where one of the two cases was observerd

Since in both callstacks below involve only/mostly code of the .Net Framework I checked the Reference Source and found really no explanation for both exceptions. I can't hardly consider another reason than corrupted memory. I am posting this question here since the second exception occured very early after start of the application, long before we load own native code via P/Invoke. At this time only the Enterprise Library (Logging Application Block) and Composite Application Library are loaded. Searching for similar problems did not bring me forward, but showed that such a problem was also observed by others (http://bytes.com/topic/c-sharp/answers/432054-strange-exception-default-hashtable-constructor and

URI constructor help with canonicalization



I have the following url: http://hi.baidu.com/%B1%F9%BA%F8%C7%EF%D4%C2 

when I use the new Uri constructor on it, it "compact the url" to a format that is not valid, I looked into the URI documentation and I found the following paragraph:

"As part of canonicalization in the constructor for some schemes, escaped representations are compacted. The schemes for which URI will compact escaped sequences include the following: file, http, https, net.pipe, and net.tcp. For all other schemes, escaped sequences are not compacted. For example: if you percent encode the two dots ".." as "%2E%2E" then the URI constructor will compact this sequence for some schemes. For example, the following code sample shows a URI constructor for the http scheme."

so it does alter the url if it has http schema, but does not touch it when it's ftp. Is there a way to force new URI constructor to not touch the url? 

I have to assign a uri object and this is screwing up the input url!


Unable to unhook an event hooked in Static constructor


One of the static constructor in a class of our project hooks to an event handler, and i tried to placed the code to unhook the event in dispose.

when i try to invoke dispose  method of the class, the object is actually null and unable to invoke dispose.

I tried using Destructor and implementing IDisposable interface, However both the destructor as well the dispose method never get called. Are they need to be called explicitly or am i missing something?. 

Is there any other elegant way to unhook the event handler? 

Note : the event handler is hooked in the static constructor.

Any help would be appreciated.



Vallarasu S.

Object cannot be serialized because it does not have a parameterless constructor


I am creating a web service based on auto-generated classes from a schema compiler and all works well until I try to run the web service.  The service is:


[WebMethod(Description="Requester pings URL of EA to see if it is alive. Returns errorObject(s) as necessary to communicate application status.")]

[SoapHeader("MultiSpeakMsgHeader", Direction=SoapHeaderDirection.InOut)]

public errorObject[] PingURL()


return null;


The class code is:


public class errorObject : Altova.Xml.TypeBase


Private Constructor


In singlton pattarn , how , when the private constructor is called , pls give some practical example

Partial Constructor


how and when a partial constructor is called, who calls the partial constructor

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