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What is syntax for creating a class in C# that would be equal to a Module in VB.net

I do almost all of my programming in VB.net (all flavors). I am now been assigned a task to make a new routine in an existing C# application. What I want to be able to do is pass a string variable to a class where I can figure out device type of a symbol handheld and figure out where an executable resides on device.
I am trying to keep the class to contain changes we make going forward in one place.
so a brief description is on a screen there will be a button. on that button click I want pass the text of the button to a (what would be a module in VB) a class and depending on text being passed and device type call a separate executable that lives on the device.
Everything I have tried so far has thrown errors.
On my button click i have
String Reponse = clsCallAction("Activity");
but that gets a message that clsCallAction is a type but is used like a variable.
here is the smaple of clsCallaction
internal static partial class clsCallAction
{
public static object GetPath(object lAppName)
{
string resp = "";
if (lAppName.Equals("Activity"))
{
resp = #"\application\activity.exe";
}
return resp;
}
}
If I put new in front of the clsCallAction("Activity") on button click I get a
cannot create instance of the static class 'clsCalACtion'
appreciate any pointers. very new at C#

It would look something like this:
public static class CallAction
{
public static object GetPath(object lAppName)
{
string resp = "";
if (lAppName.Equals("Activity"))
{
resp = #"\application\activity.exe";
}
return resp;
}
}
And would be used like this:
String Reponse = CallAction.GetPath("Activity");
Don't prefix classes with cls
Avoid using object if possible - it just makes everything harder work than it needs to be.. Kinda like calling everything "thing" - ("Put the thing in the thing and open the thing" is harder to understand than "put the key in the lock and open the door")

Storing global variables in c#?

I basically have created a class which when a user logs into a website it then queries the database and stores some settings in a List (So I have key/pair values).
The reason for this is because I want to always be able to access these settings without going to the database again.
I put these in a class and loop through the fields via a SQL query and add them to the list.
How can I then access these variables from another part of the application? or is there a better way to do this? I'm talking server side and not really client side.
Here is an example of what I had at the moment:
public static void createSystemMetaData()
{
string constring = ConfigurationManager.ConnectionStrings["Test"].ConnectionString;
SqlConnection sql = new SqlConnection(constring);
sql.Open();
SqlCommand systemMetaData = new SqlCommand("SELECT * FROM SD_TABLES", sql);
//Set Modules
using (SqlDataReader systemMetaDataReader = systemMetaData.ExecuteReader())
{
while (systemMetaDataReader.Read())
{
var name = systemMetaDataReader.GetOrdinal("Sequence").ToString();
var value = systemMetaDataReader.GetOrdinal("Property").ToString();
var Modules = new List<KeyValuePair<string, string>>();
Modules.Add(new KeyValuePair<string, string>(name, value));
}
}
}
Thanks

Any static properties of a class will be preserved for the lifetime of the application pool, assuming you're using ASP.NET under IIS.
So a very simple class might look like:
public static class MyConfigClass
{
public static Lazy<Something> MyConfig = new Lazy<Something>(() => GetSomethings());
public static Something GetSomethings()
{
// this will only be called once in your web application
}
}
You can then consume this by simply calling
MyConfigClass.MyConfig.Value

For less users you can go with the SessionState as Bob suggested,however with more users you might need to move to a state server or load it from Data Base each time.

As others have pointed out, the risk of holding these values in global memory is that the values might change. Also, global variables are a bad design decision as you can end up with various parts of your application reading and writing to these values, which makes debugging problems harder than it need be.
A commonly adopted solution is to wrap your database access inside a facade class. This class can then cache the values if you wish to avoid hitting the database for each request. In addition, as changes are routed through the facade too, it knows when the data has changed and can empty its cache (forcing a database re-read) when this occurs. As an added bonus, it becomes possible to mock the facade in order to test code without touching the database (database access is notoriously difficult to unit test).

From the looks of things you are using universal values irrespective of users so an SqlCacheDependency would be useful here:
Make sure you setup a database dependency in web.config for the name Test
public static class CacheData {
public static List<KeyValuePair<string,string>> GetData() {
var cache = System.Web.HttpContext.Current.Cache;
SqlCacheDependency SqlDep = null;
var modules = Cache["Modules"] as List<KeyValuePair<string,string>>;
if (modules == null) {
// Because of possible exceptions thrown when this
// code runs, use Try...Catch...Finally syntax.
try {
// Instantiate SqlDep using the SqlCacheDependency constructor.
SqlDep = new SqlCacheDependency("Test", "SD_TABLES");
}
// Handle the DatabaseNotEnabledForNotificationException with
// a call to the SqlCacheDependencyAdmin.EnableNotifications method.
catch (DatabaseNotEnabledForNotificationException exDBDis) {
SqlCacheDependencyAdmin.EnableNotifications("Test");
}
// Handle the TableNotEnabledForNotificationException with
// a call to the SqlCacheDependencyAdmin.EnableTableForNotifications method.
catch (TableNotEnabledForNotificationException exTabDis) {
SqlCacheDependencyAdmin.EnableTableForNotifications("Test", "SD_TABLES");
}
finally {
// Assign a value to modules here before calling the next line
Cache.Insert("Modules", modules, SqlDep);
}
}
return modules;
}

The following throws 'is a Method but treated like a type'

The most confusing error I have ever seen in ASP. I have done method calls like this before, and have no issue in other spots of my code.
First of all the class:
namespace LocApp.Helpers.Classes.LocationHelper
{
public class QueryHelper
{
private LocAppContext db = new LocAppContext();
public static IEnumerable<Service> getAllService()
{
using (var db = new LocAppContext())
{
var service = db.Locations.Include(s => s.LocationAssignment);
var serv = (from s in db.Services
where s.active == true
select s).ToList();
return serv;
}
}
}
}
Pretty easy to understand whats going on. So lets call the method:
IEnumerable<LocApp.Models.Service> Service = new LocApp.Helpers.Classes.LocationHelper.QueryHelper.getAllService(Model.id);
getAllServices(Model.id) is throwing the error "is a method but treated like a type" , um no its not be treated like a type....
whats going on?

Well it's exactly as the error message says. getAllService() is a method:
public static IEnumerable<Service> getAllService()
But you're trying to use it as if it were a type with a constructor:
Service = new LocApp.Helpers.Classes.LocationHelper.QueryHelper.getAllService(...)
The new part is the mistake here. You don't want to call a constructor, you just want to call a method. It's a static method, so you don't need an instance - you can just use:
Service = LocApp.Helpers.Classes.LocationHelper.QueryHelper.getAllService(...)
Note that if you have appropriate using directives, follow .NET naming conventions and take care about singular/plural names, your code will be easier to follow:
var services = QueryHelper.GetAllServices(...);

Do you not simply mean:
IEnumerable<LocApp.Models.Service> Service = LocApp.Helpers.Classes.LocationHelper.QueryHelper.getAllService();
Get rid of the new bit, essentially, and that method doesn't take any parameters either - I'd assume you'd run into that problem after you removed the new bit.

Your getAllService method doesn't take any arguments, so you should call it without. Also it is a static method so don't use the new keyword:
IEnumerable<LocApp.Models.Service> Service = LocApp.Helpers.Classes.LocationHelper.QueryHelper.getAllService();

"Use of unassigned local variable" error with an Interface

I'm having trouble with some syntax. I'm not really familiar with interfaces so please excuse my ignorance.
VS2010 is giving me an error at... application.Name = System.AppDomain.CurrentDomain.FriendlyName;
public static void AddApplication(string applicationName = null, string processImageFileName = null)
{
INetFwAuthorizedApplications applications;
INetFwAuthorizedApplication application;
if(applicationName == null)
{
application.Name = System.AppDomain.CurrentDomain.FriendlyName;/*set the name of the application */
}
else
{
application.Name = applicationName;/*set the name of the application */
}
if (processImageFileName == null)
{
application.ProcessImageFileName = System.Reflection.Assembly.GetExecutingAssembly().Location; /* set this property to the location of the executable file of the application*/
}
else
{
application.ProcessImageFileName = processImageFileName; /* set this property to the location of the executable file of the application*/
}
application.Enabled = true; //enable it
/*now add this application to AuthorizedApplications collection */
Type NetFwMgrType = Type.GetTypeFromProgID("HNetCfg.FwMgr", false);
INetFwMgr mgr = (INetFwMgr)Activator.CreateInstance(NetFwMgrType);
applications = (INetFwAuthorizedApplications)mgr.LocalPolicy.CurrentProfile.AuthorizedApplications;
applications.Add(application);
}
I can make that error go away by setting application to null but that causes a run-time null reference error.
Edit:
Here's where I'm adapting the code from. I hope it gives more context
http://blogs.msdn.com/b/securitytools/archive/2009/08/21/automating-windows-firewall-settings-with-c.aspx

You never initialize
application
before using it here:
application.Name = System.AppDomain.CurrentDomain.FriendlyName;
The variable application is defined as:
INetFwAuthorizedApplication application
You need to assign an instance of a class that implements the interface INetFwAuthorizedApplication.
Somewhere there must be one (or probably more) classes in your project that look something like this:
public class SomeClass : INetFwAuthorizedApplication
{
// ...
}
public class AnotherClass : INetFwAuthorizedApplication
{
// ...
}
You need to determine what class you should use (SomeClass, AnotherClass) then assign an appropriate object, e.g. like this:
INetFwAuthorizedApplication application = new SomeClass();

Interfaces are used to describe what an object does, not what it is specifically. To put into "real world" terms, an interface might be like:
ISmallerThanABreadbox with a FitIntoBreadbox() method. I can't ask you to give me "the smaller than a breadbox" ... as that doesn't make any sense. I can only ask you to give me something that "IS smaller than a breadbox". You have to come up with your own object that makes sense to have the interface on it. An apple is smaller than a breadbox, so if you have a breadbox that only holds items smaller than it, an apple is a good candidate for the ISmallerThanABreadbox interface.
Another example is IGraspable with a Hold() method and FitsInPocket bool property. You can ask to be given something that IS graspable that may or may not fit in your pocket, but you can't ask for "the graspable".
Hope that helps...

LINQ to SQL Field Won't Update (Sometimes)

I have a MVC Web Application using the following approach:
public class MyController : Controller
{
public FooRepository fooRepository = new FooRepository();
public BarRepository barRepository = new BarRepository();
public ActionResult UpdateItems(int id, int range1, int range2)
{
Foo foo = fooRepository.GetItem(id);
List<Bar> bars = barRepository.GetItemsByRange(range1, range2);
// Some validation rules here...
DoSomeWork(foo, bars);
// Show confirmation / error message
}
private void DoSomeWork(Foo foo, List<Bar> bars)
{
foreach(int i = 0; i < bars.Count; i++)
{
bars[i].Prop1 = foo.Prop1; // This field is updated
bars[i].Owner = "someuser"; // This one too
bars[i].Status = BarStatus.SomeStatus; // This isn't...
}
foo.Status = FooStatus.SomeStatus; // Ok
// Calls DataContext.SubmitChanges()
fooRepository.SubmitChanges();
barRepository.SubmitChanges();
}
}
However, in some "random" cases (I see no pattern), one of the fields doesn't get updated, as noted in the comments.
It seems like LINQ isn't recognizing the field's update, so it gets excluded from the generated query.
Can anyone tell me if I'm missing something here, what could be causing it and/or how can I solve it?
Note: I don't get any Exception and can't verify this case in a development scenario.

From my experience if the error is random and you can't reproduce in development than the problem is user error.
Programming would be really hard if the .net framework or the CLR just randomly decided to do things differently.

You probably have an implicit/explicit bind exclusion floating around somewhere
[Bind(Exclude="...,Status,...")]
Just guessing of course

If Linq thinks that the Status is already BarStatus.SomeStatus, then it won't update it.
What can happen is that you find a record with the status set to this value, and then some other routine changes it, and then, if you are using your same DataContext, you will get the old value from the cached copy and hence Linq thinks that it does not need to update it.