MVC :: Exception Calling UpdateModel - Value Cannot Be Null Or Empty
Apr 8, 2010
This is probably something silly I'm missing but I'm definitely lost. I'm using .NET 4 RC and VS 2010. This is also my first attempt to use UpdateModel in .NET 4, but every time I call it, I get an exception saying Value cannont be null or empty. I've got a simple ViewModel called LogOnModel:
[Code]....
My view uses the new strongly typed helpers in MVC2 to generate a textbox for username and one for the password. When I look at FormCollection in my controller method, I see values for both coming through.
And last but not least, here's are post controller methods:
I have code that's working beautifully on my development machine,but when deployed to the server is throwing null reference exception.So,I can't step through the code,but I've pinned down the culprit.But now I am puzzled.Here's the code.The question is below.
Dim certs = From p In persons _ Select New Certificate( _ p.Value, _ New CertificateData.Seminar(thisEvent.Seminar.Name, _
[code]...
In the code above persons is a dictionary of custom class,and certs is of IEnumerable type.Now here's the quandary.The first line that sets the label returns False,so certs is not null.But the second line throws an null reference exception.
I have just upgraded a large project to MVC 2 (50+ controllers) and whilst the project builds fine I am having issues in several places because it looks like the way the Controller.UpdateModel method handles emtpy strings has changed.
In MVC 1 it set the associated property to an empty string but in MVC2 it's setting it to null.
I have setup my business object to have a create_date and edit_date members both datetime datatypes. My company want to display the create_date and edit_date fields in a gridview for each transaction. The problem i have is that after insterting a record it will have a valid create_date but no edit_date and when displayed in the gridview it defaults to datetime.minvalue (My default). How on earth do i show an empty field in my gridview for a null datetime field in the database?
I am using similar architecture to the Imar Spaanjaars example of a tiered solution. With a few small tweeks it has worked well for me for ages. I am passing a List<Database> to my object datasource which connects to my gridview.
I have simple 3 tier web application and have mostly CRUDE functionalities. Recently I required to add new console application to the existing solution in which I call data layer methods for retrieving data from DB but I get an exception "The type initializer for threw an exception."When I debugged I found that the exception is thrown at datalayer on first line of class where I get connectionstring from
web.config, the code is public static readonly string CONNECT_STRING =
Now if I hardcode the connection string value like public static readonly string CONNECT_STRING = "Data Source=XYZ;uid=sa;password=XXX;initial catalog=ABC;"
it works fine.I don't understand what is the issue here as web application works fine with this datalayer.
I am using AjaxToolkit 4.0 which suggests to use ToolkitScriptManager in place of ScriptManager. But when I am using ToolkitScriptManager, it throws javascript exception when Page_ClientValidate() in called from javascript. However, this error is not coming when ScriptManager is used. Can anybody tell me how to make Page_ClientValidate() run when using ToolkitScriptManager?
I'm trying to implement a view tracking web service on my website. I'm using JavaScript because I want to exclude any search bots from my tracked views. The problem is I'm getting a "Unknown web method" error when I try to use jQuery to post to the web service I've created.
$(document).ready(function() {
$.ajax({ type: "POST", [code]...
The error is an ASP .NET error: Unknown web method TrackItemView. Parameter name: methodName.I've done this hundreds of times (seemingly), but I just can't see what I'm missing. I'm sure it's something small...
The way this page is laid out, all of the data is loaded at Page_Init. Well, I have a custom control that is having problems with this though.
I have it on the page like so:
<cc:SomeControl... />
And then I set the value at Page_Init using
MyControl.Value="blah";
Simple stuff..
The Value is an accessor and has something similar to this:
public string Value{ get... set{ EnsureChildControls(); MyHiddenField.Value=value; } }
and it is here that I have a problem. It says that MyHiddenField is null. Is Page_Init just too early for this? Or is there some other function I need to call?
I have a class library which has my LINQ doc in it. I added a stored procedure and I get the following in my .dbml.layout :
[Code]....
I include a reference to the dll of the class library to my web project and I get an error about value being returned as int where I am trying to put contents into a datalist or similar.
Code in class that calls this SP :
[Code]....
So I switched code to the following in my dbml.layout document :
I'm using a static Timer in my Global.asax to run a method at regular intervals. When the method throws an exception, my application is stopped. I have used an empty catch to prevent exceptions from stopping the application something like below code. Is there a disadvantage to use such an approach?
I'm getting a null reference exception whenever I try to databind this datatable to the Gridview. I know for sure that the datatable has data. I've checked it.
[Code]....
I get the error when it gets to the last line here..
I have set the value of an int parameter to the attribute of a textbox.The textbox can be empty or null, how to check whether the parameter is empty or null?
Im trying to resize an image. I have the original file and then try to resize it and save it to a new image.However, I get an exception because the value of stream cannot be null. This makes sense, but I dont know how to prevent it:
Value cannot be null. Parameter name: stream Description: An unhandled exception occurred during the execution of the current web request. Source Error:
I have a TextArea html helper method I'm calling in a foreach loop. Basically, when I initially load the View it works fine, but when i reload the View and load postback data, the same TextArea throws a NullReferencException and yet the variable I'm using in the TextArea as the name of the TextArea is not null. I've attached a picture below for demonstration:
if it's difficult to see, the blue arrow below is pointing to the variable used to name the TextArea. Again, it works on initial load, but it errors out on postback when the page is reloaded. I'm not sure what's going on.
I have pass following SQL Query to the through ObjectDataSource
[Code]....
And I am passing parameter through QueryString and My idea is like when empty string is pass it should show me all records but when I am passing empty string ObjectDataSource is making NULL and I am not getting desire result
I have a form and stored procedure that inserts the data from the form. It works fine except that if a field isn't filled in it doesn't insert a NULL into sql it inserts "".
I've tried a few different ways but none seem to insert NULL, the one below still inserts "", can anyone point me in the right direction.
Here is the required part of the code, if you require more just let me know.
[code]....
So if I enter nothing into address1 field it should write NULL to screen but it always writes NOT NULL.
