MVC :: System.MissingMethodException: No Parameterless Constructor Defined For This Object - How To Fix This Error
May 11, 2010
I've set up a strongly-typed View and a controller method to save the object represented in that View. The object in question is from a class that uses named parameters with default values. This is not a database object, but rather is the intermediate object that is used for the display and user input. It gets translated into a database object in the service class. Anyway, when I attempt to save the object, I get the following error:
System.MissingMethodException: No parameterless constructor defined for this object.
This is kind of aggravating. I can add a parameterless constructor to the class, and then everything works just fine. I just don't understand why it is necessary. I'm new to named parameters with default values, but the reading and such that I've done has described that method calls with default values do not have to have a 'no-parameter' implementation. You can just call the method with any or none of the parameters specified and everything works as expected. If there is a 'no-parameter' implementation and no params are passed, then that one is used, since it is more specific than the one with default values. Is the behavior somehow different when this is used in the constructor of a class? Why would I have to include a parameterless constructor when I have all the values accounted for? Is the runtime creating an object on the fly as the save method executes, which requires this? The method is like this:
[Code]....
I'm wondering if the object is instantiated by the runtime in order to populate the method parameter, and then assigned values from the form collection. I suppose that would make sense, but I do not understand why this causes an exception. For what reason would a parameterless constructor be required?
I'm very new to Visual Studio and I am getting this error when trying to update an Oracle table from Gridview using a tableadapter datasource. I've followed the instructions in my text very closely but am at a loss as to why this error is occurring.
Details: System.MissingMethodException: No parameterless constructor defined for this object.
Source Error:
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Stack Trace:
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this is the stack trace error I am getting. At this point, I'm a little clueless how to resolve it.
I receive the error "No parameterless constructor defined for this object", I have read some post on this forum about this error, but i cannot get it to work.
First I incorrectly had my node defined in /shared/web.config instead of the web.config in the root of the WebUI project. I also had not correctly defined my connection string within web.config. I have pasted the proper web.config sections below:
I have no idea why my form submit is not passing the model back to the Controller action
Here is the View:
[Code]....
Heres the Controller:
[Code]....
Here is my Model:
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By default Index, renders with an empty results set, on button press i want it to go to the "StartSearch" Action, and rerender the index with possibly non-null results set.
Does anyone have any good examples of how to make Unity 1.2 or 2.0 work with ASP.NET WebForms?
I thought I had this figured out, but evidently I'm missing something. Now I'm getting the error; "No parameterless constructor defined for this object". I remember getting this error a couple years ago, I and just don't remember what I did.
Obviously Unity isn't working as it should because somewhere along the way I've forgotten something.
I have impelemented my own mvc pattern to my website , when I add desired type for my ObjectDataSource pointing to the controller class although GridView refreshes schema in designer just fine I get an error in runtime saying : "No parameterless constructor defined for this object." which is self explaining but I wonder why does it happening because I've used this pattern once and didn't have that issue , here is the bit of code that is causing this issue , what to do to keep my mvc and make it work :
I have a usercontrol which implements iwebpart and this is loaded into a webpart by adding it to the webpartmanager on the page. But i'm getting the error message "No parameterless constructor defined for this object." and i cannot find out what i'm doing wrong. The control is loaded into the webpart by:
I've created a web service , which can a method to set the user credential using Microsoft.Web.Services3.WebServicesClientProtocol. The sample code is :
<WebMethod()> _ Public Sub ClientCredential1(Of TSecurityToken As SecurityToken)_ (ByVal UserCred As Microsoft.Web.Services3.Security.Tokens.UsernameToken)
[code]....
When I run the web service it gives this error: "Microsoft.Web.Services3.Security.Tokens.UsernameToken cannot be serialized because it does not have a parameterless constructor."
i am taking data from two tables so i created one class and i constructed with two tables like this..
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my edit post method is:
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if i put PublisherViewModel in post function edit (ByVal aintEntityId As Integer, ByVal model As PublisherViewModel) As ActionResult. i am getting this error when post edit function called. No parameterless constructor defined for this object.
I created a small new webservice for AutoCompleteExtender and for some reason I am getting "type System.Web.Script.Services.ScriptService is not defined" error. I Googled this and found a few threads about similar issues but was unable to resolve mine. Here is the example of the code:
[Code]....
When I add Imports System.Web.Script.Services I get "Namespace or type specified in the Imports 'System.Web.Script.Services' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases".
I've tried adding Reference to System.Web.Extensions and it didn't do anything. What could be the problem?
I have written my ASP.NET web site code in Visual Studio 2008. When I'm uploading it to the remote server I'm getting an error message about a problem in the web configuration file:
Section or group name 'system.web.extensions' is already defined.Updates to this may occur at the configuration level where it is defined.What is the reason for this error?
I have problem on my server 2003 R2 with .NET Framework 3.5
When i try to send mail using System.Net.Mail in Web Application, the following problem occurs:
Server Error in '/EmailTeste' Application.
Object reference not set to an instance of an object.
Description:
An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
[Code]....
[code]....
When i using the System.Web.Mail, the application work correctly.
Why i have to do for the web server send mail using System.Net.Mail?
when we declared as static then we will not create the object to call the static method. then my doubt is how is call the static constructor after creating the object?can you explain cleary?
I receive the following error in the code below: System.NullReferenceException: Object reference not set to an instance of an object. When I am logged into the page I do not receive the error. My Code:
Partial Class _Default Inherits System.Web.UI.Page Protected Sub SqlDataSource4_Selecting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs) Handles SqlDataSource4.Selecting Dim MemUser As MembershipUser MemUser = Membership.GetUser() UserID.Text = MemUser.ProviderUserKey.ToString() e.Command.Parameters("@UserId").Value = MemUser.ProviderUserKey.ToString() End Sub End Class
I read the following online: You are trying to use a reference variable who's value is Nothing/null. When the value is Nothing/null for the reference variable, that means it is not actually holding a reference to an instance of any object that exists on the heap. You either never assigned something to the variable, never created an instance of the value assigned to the variable, or you set the variable equal to Nothing/null manually, or you called a function that set the variableto Nothing/null for you. The following is the Arthur's code example and his suggested fix which I am sure is right:
Private Sub TestString() Dim a As String If a.Length = 0 Then Console.Write("Yes") End If End Sub
I am trying to pass a collection of Dropdown controls as a parameter to a method which takes a collection of type Control as input. While executing I get the following error:
"Unable to cast object of type 'd__a31[System.Web.UI.WebControls.DropDownList]' to type 'System.Collections.Generic.IEnumerable1[System.Web.UI.Control]'."
This error is occuring randomly, and I can't seem to pinpoint what is causing it. For the most part, the code works fine. I'm confused why it works sometimes, but then suddently craps out on me, lol.It happens in the code when I call upon the asp.net membership provider. It only seems to happen when i use Membership.GetUser() to grab the logged in user's information.
So, I've been programming for a number of years. Finding some intricately asinine issues w/ ASP.NET and VB.NET as I learn them. How about this one:
[Code]....
The issue is not Date1 The issue is Date2.
No kidding. I had to String.Format Date1 for some odd reason, even though I'd already validated it. And, yes, I tried to parse and convert Date1 but I kept gettting the typical "Argument 'Date2' cannot be converted to type 'Date'." error. (Did you catch the copy & paste? I didn't edit it from my existing error, but Date2 should be Date1.) Yeah, that's the error I'm getting now with the above ...
"Argument 'Date2' cannot be converted to type 'Date'."
Date2 is a system defined type. Why can't the system convert and/or simply use it's own pre-defined type?
I'm getting the error from the subject line when I try to move some code that formerly lived in the App_Code directory to an external library (that would be moved into the /bin directory). What do I need to include or reference to get rid of this error?
I've already included: System.Runtim.Serialization (says it's version 3.0.0, I don't see a version 3.5.0 anywhere).
I am trying to create an MVC2 web application that will run both on my local development machine (on localhost), and on our central webserver.
Development machine:
Windows 7 Professional, 64bitVisual Studio 2010 (beta)ASP.NET 4.0IIS 7.5
Webserver:
Windows Server 2003 SP2ASP.NET 3.5 SP1 (determined by checking the folders under %SystemRoot%Microsoft.NETFramework)IIS 6.0
Everything works fine when debugging from VS, and I've finally gotten so far that it also works copied to the webserver. However, when I try to copy it to my own local webserver, I get the following error message:
Error Summary
HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.
