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.
this is the stack trace error I am getting. At this point, I'm a little clueless how to resolve it.
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'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:
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?
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 am taking data from two tables so i created one class and i constructed with two tables like this..
my edit post method is:
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.
when i click "submit button" on my page it's show this error..where is the problem actually?
"Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation."
i have post detail page (asp.net, umbraco cms), with search box and post replay box.the problem is that when user try to search using the search box, it cause validation error in the post replay box.the search is client side form.the post replay is server side form.you can view it live at:[URL]
I've been trying to figure this out all afternoon but my google-fu seems to be failing me. I'm setting up a page with a fairly large form, which has one field that is going to require some kind of popup page that will allow the user to perform a lookup.
At the moment I'm only prototyping the page so I'm actually only attempting to a the button up to fire an alert when the button is clicked instead of generating a lookup screen. However it seems that no matter what I do the button causes the form to submit.
I remember one of the very first ASP .NET beginner videos I ever watched went through configuring a button to perform actions without submitting, but I can't seem to figure out which one it was.
Each time i click the submit button i get this error:Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.
I am loading an external file 'contact_us.aspx' into a jquery dialog box. the external page contains a form.When the submit button is pressed it closes the dialog box and changes the page to contact_us.aspx. is my code correct or is there a different way of doing this. see my code below, thanks.