Introduction
While I was working on one of my projects, I got into a situation where I needed to get the current ApplicationContext
instance from one part of my software. I started my research on MSDN, then on the Internet. As some of you probably already know by reading this article, I did not find the results I was looking for. I cannot understand why there is no easy way to get the current ApplicationContext
instance with regular MS defined properties or methods. I have, however, created a simple solution.
The code
- Create a new class inherited from
ApplicationContext
:
public class CurrentAppContext : ApplicationContext
{
public CurrentAppContext()
{}
}
If you need to set the Main Form for ApplicationContext
while initializing it, you can add the constructor like this as well:
public CurrentAppContext(Form AppMainForm)
{
this.MainForm = AppMainForm;
}
- Create a
public static
field of our class of type CurrentAppContext
inside of the class.
public class CurrentAppContext : ApplicationContext
{
public static CurrentAppContext CurrentContext;
public CurrentAppContext()
{}
public CurrentAppContext(Form AppMainForm)
{
this.MainForm = AppMainForm;
}
}
- Because
static
class fields exist only once and are not created again, when we create a new class instance, we can initialize our field from the constructor.
public class CurrentAppContext : ApplicationContext
{
public static CurrentAppContext CurrentContext;
public CurrentAppContext()
{
CurrentContext = this;
}
public CurrentAppContext(Form AppMainForm) : this()
{
this.MainForm = AppMainForm;
}
}
- If you need to get the
ApplicationContext
at run time, we will create a new instance of CurrentAppContext
and get CurrentContext
, which is exactly what we need (see below):
CurrentAppContext _curContext = (new CurrentAppContext()).CurrentContext;
OOPS! Because we initialize CurrentAppContext()
again and point CurrentContext
to new CurrentAppContext
instance, CurrentContext
will be referring to the new instance, but not to our current ApplicationContext
. We have to add (If
) statement to constructor and make sure that if the CurrentContext
is not null
, we do not make a new assignment. Also, let’s convert public
field to Read Only property.
Final class will look something like this:
public class CurrentAppContext : ApplicationContext
{
private static CurrentAppContext _currContext;
public CurrentAppContext()
{
if (_currContext == null)
{_currContext = this;}
}
public CurrentAppContext(Form AppMainForm) : this()
{
this.MainForm = AppMainForm;
}
public CurrentAppContext CurrentContext
{get { return _currContext; }}
}
Now, you can create it inside Main()
as usual and get it from any part of your software. If necessary, you can extend it with new fields and methods.
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.