I am getting an exception like"NullReferenceException was unhandled by usercode-Object reference not set to an instance of an object." in (IEnumerable)Viewdata.Model.
<% foreach (EmployeeMaster m in (IEnumerable)ViewData.Model)
Look below this codes throw me : FormatException was unhandled by user code
Codes:
satis.KDV = Decimal.Parse((from o in genSatisctx.Urun where o.ID == UrunID select o.Kdv).ToString()); How can i rewrite linq query?
My company has an application that handles shopping cart check out processes.The application is written in VB.net with the .NET 2.0 Framework.We are running IIS 6.0 as the web server and have,what we consider,excellent exception handling.For those exceptions that we can't figure out why they're happening,we use Elmah to handle them,package them up,and email them to us.We still see a fair amount of unhandled exceptions,handled by Elmah.
My question is:This is an application that is used by many people on the web at the same time.If there is an unhandled exception (handled by Elmah, mind you),does this then reset the application so that all users who aren't doing anything naughty see the application blow up in front of them when this happens?
my web application has more than one user with unique usercode. As soon as a new record is inserted into the database with some usercode, i want to show a popup only to that user in his browser window. for example insert into mytable(usercode) values(1431) is inserted into my databasetable.if user with usercode 1431,1435 are loggedin. i want to show the notification only to the user with usercode=1431
View 2 Repliesan unhandled win32 exception occurred in w3wp.exe error occures when we run .Net application from IIS. My configuration is Windows server 2008, IIS7, .Net 2.0, and Oracle 10g.
View 2 RepliesIn my experience building web applications, I've always used a n-tier approach. A DAL that gets data from the db and populates the objects, and BLL that gets objects from the DAL and performs any business logic required on them, and the website that gets it's display data from the BLL.I've recently started learning LINQ, and most of the examples show the queries occurring right from the Web Application code-behinds(it's possible that I've only seen overly simplified examples). In the n-tier architectures, this was always seen as a big no-no.I'm a bit unsure of how to architect a new Web Application.
View 2 RepliesI'm trying to use linq to sql for my project (very short deadline), and I'm kind of in a bind. I don't know the best way to have a data context handy per request thread. I want something like a singleton class from which all my repository classes can access the current data context. However, singleton class is static and is not thread-safe and therefore not suitable for web apps. I want something that would create a data context at the beginning of the request and dispose of it along with the request
View 1 RepliesWill linq to sql work in an asp.net 2.0 web applicationJust realized the server doesnt' support asp.net 3.5 (no control over it
View 3 RepliesI am developing sample web application which use C#, and LINQ to SQL. The application is very very slow and it takes about 2 secs to navigate between pages. I have already used SQL Profiler and monitor the calls to the SQL server. All SQLs looks normal to me and their execution time is always about 1 or 2 millisecs.I tried the same application in another PC and it is the same. So, it is not because of my computer performance.
View 3 Repliesi want define connectionSreing in the web.config and then use it for DataContext ConnectionString. i do that : 1. i creat a class in App_Code :(MisaghDB is my database)
partial class MisaghDataContext
{
partial void OnCreated()
{
this.Connection.ConnectionString =
ConfigurationManager.ConnectionStrings["MisaghDBConnectionString"].ConnectionString;
}
// or
public partial class MisaghDataContext
{
public MisaghDataContext() : base (ConfigurationManager.ConnectionStrings["MisaghDBConnectionString"].ConnectionString)
{
OnCreated();
}
}
}
2. Add the connection string to my web.config file:
<configuration>
<connectionStrings>
<add name="MisaghDBConnectionString" connectionString="Data Source=NAZLIN-HP;Initial Catalog=MisaghDB;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>
3. Right click on the DBML file design surface and chose properties. Select "none" for the Connection property.now should i change DBML file designer.cs (Misagh.designer.cs) ? The code should I delete in this file(DBMLfile designer.cs)? this is a part of my DBMLfile designer.cs :
[global::System.Data.Linq.Mapping.DatabaseAttribute(Name="MisaghDB")]
public partial class MisaghDataContext : System.Data.Linq.DataContext
{
private static System.Data.Linq.Mapping.MappingSource mappingSource = new AttributeMappingSource();
public NorthwindDataContext() :
base(global::WindowsFormsApplication2.Properties.Settings.Default.NorthwindConnectionString, mappingSource)
{
OnCreated();
}
public NorthwindDataContext(string connection) :
base(connection, mappingSource)
{
OnCreated();
}
public NorthwindDataContext(System.Data.IDbConnection connection) :
base(connection, mappingSource)
{
OnCreated();
}
public NorthwindDataContext(string connection, System.Data.Linq.Mapping.MappingSource mappingSource) :
base(connection, mappingSource)
{
OnCreated();
}
public NorthwindDataContext(System.Data.IDbConnection connection, System.Data.Linq.Mapping.MappingSource mappingSource) :
base(connection, mappingSource)
{
OnCreated();
}
............}
I am trying to handle concurrency in my application. Basically if user A has a support ticket open which currently has a status of 'Active' and user 'B' opens the same ticket and closes it (changing its status to closed), I would expect a confict execepton to be thown when user 'A' tries to close the support ticket. For some reason this is not happening. I have checked that Update check is set to 'Always' in the dbml file. Here is an exerpt of my code. // Update 'Active' lead to 'Close'
[Code]....
i am curious to know which is generic way to create DAL which can be used to large application and small applications using ?
1) What can i use to create large application Linq to Sql OR Entity Framework Or Any others ?
I have the following problem;My console app is running on the server and all I want to do is control it over ASP.NET Web Service.
I added new ASP.NET Web Service project to my Solution where my main console app and added reference to it.The problem is every time WebMethod calls function from console app, i get the nullreferenceexception. Even if I try to use static classes or singletons; every object is null, although my console app is running absolutely correctly.
m a pretty new developer so I'm not well versed in common ASP.NET problems.As a test, my boss asked me to convert a (not very critical) ASP.NET site from 1.1 to 4.0. Well, it's not extremely difficult and things are going well so far. However, I've hit a small snag. I keep getting a NullReferenceException when I run this code
View 1 RepliesI am getting a NullReferenceException thrown when trying to add to theList object. Clueless at this point about how to solve.
[Code]....
When I submit invalid data to test my form validation I get a NullReferenceException on the folloing line of code in my view:
[Code]....
I can't seem to find anything that's null.assessment.AssessmentDescr is populated with the expected string.assessment.Score is populated with the value 0.Any ideas as to what might be causing the NullReferenceException? Seems to me that Html.TextBox has everything it nees to render the TextBox.
I followed the directions from MSDN on transferring data between asp.net pages.But when using the 'PreviousPage' property to access the previous pages controls, I get a null ref exception that PreviousPage is not set to an instance of an object.Here is my code:
public partial class Portal : System.Web.UI.Page
{
public string Username
[code]...
we have an MVC app that is after some time getting to some kind of bad state. I found only a couple of posts with a similar error message and they pointed to not changing up the routing table (after appstart). However this app doesn't mess with the routing table after appstart so that would appear not to be the cause of our problem. Recycling the app makes the error go away... for a time. Got 3 sites (all running of the same codebase) that this is effecting.
Just incase I'm doing something naughty in my application class heres a bit of source:
[Code]....
And the class that inherits from: [Code]....
Stack trace follows:[NullReferenceException: Object reference not set to an instance of an object.]
System.Web.Routing.RouteCollection.GetVirtualPath(RequestContext requestContext, RouteValueDictionary values) +97
is it good for desktop application (WCF) or web application.I am little confuse about LINQ functionalities i have read some articles which are discourage LINQ (due to poor performance) for web applica
View 3 RepliesI have question about N-tier architecture. everyone about 3-Layer architecture these are:
1). UI Layer,
2). Business Layer,
3). Data Access Layer.
i already have worked on this.
Then i heard about LINQ to sql. how many layer an web application should contain.
As my knowledge. if i use LINQ to slq then i have to worked only 2-Layer:
- Data Acess/Business Layer: which contains only *.dbml files which is my database and
- UI Layer: which contains *.aspx files.
As a test, my boss asked me to convert a (not very critical) ASP.NET site from 1.1 to 4.0. Well, it's not extremely difficult and things are going well so far. However, I've hit a small snag. I keep getting a NullReferenceException when I run this code:
[Code]...
I'm trying to call a dataadapter funtion to pass browser information to a database table upon logged in. I have also tried not assigning the function to an interget by setting the fucntion to not return a value. However in either case I get the System NullReferenceException.
[Code]....
I have some inline code in an aspx file that executes:
<dd><%= encode(Listing.Address.Line1) %> </dd>
Problem is, under certain circumstances the Listing object will be null and therefore references to properties such as Address will throw an exception. How do I handle that exception? I basically want to ignore it: catch it, and then proceed with regular execution/rendering of page.
how to improve the application performance while writing LINQ Queries ?Like the optimization techniques.
View 2 RepliesI have question about N-tier architecture. everyone about 3-Layer architecture these are:1). UI Layer, 2). Business Layer, 3). Data Access Layer.i already have worked on this.Then i heard about LINQ to sql. please tell me how many layer an web application should contain. As my knowledge. if i use LINQ to slq then i have to worked only 2-Laye
View 9 Replies
