At work, we are about to build a new internal tool for administration of different
systems. We developers need certain applications and the sales department needs some
other ones. All the different people need to be able to administrate different systems, so we decided to create one application that hosts only the applications the individual
needs.
Last weekend I played with a generic application that hosts other applications by
using reflection. The Plug-in Application does nothing but manages the different
plug-ins and let you add and remove plug-ins as you please. When a plug-in is added, it is added to the menu so that every time you open the application, you have easy
access to the plug-in.
Each plug-in is in essence a .NET Windows Forms application, but you can also compile
the WinForm into a .dll file so it cannot be opened outside the application.
This is what it looks like when the plug-in “TestForm” is running in the application.
Now the plug-in is maximized.
By clicking on the menu item “Manage Plug-ins” it pops up a manager that lets you
add and remove plug-ins.
How it works
To make your Windows Forms application compatible with the application, you need to
let the main form inherit from a class called PluginForm. The PluginForm resides
in its own assembly and is also referenced by the Plug-in Application. It
only contains a property called Description and that is used to display tooltips
on the menu and in the Plug-in Manager. Your main form needs to inherit from the PluginForm
in order to know which form is the one to use in the Plug-in Application.
When you add a plug-in then the Plug-in Application creates an XML document
that describes its location, icon, description and name. Because it does not copy
the .exe or .dll file but only points to it, means that app.config and other files
still work with the plug-in.
This is a simplified version of the one we need at Traceworks where
we also needs security and other features. The Plug-in Application is so
simple that it is easy to add such features.
Download
The solution contains three projects. The application, the PluginForm base
class project and a test plug-in.
PluginApplication.zip
(243,15 KB)
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