Are you asking how to import an image file using a dll into a picturebox that's already in your application?
I created 2 application in c#
one is working with file and the secend is doing some thing else,
my question is how can I create a dll file from the first application and put it into application number 2.
I wot to create Dll file like in this artical
Making a dll is easy in VC# and I hope that's what you're using. You can easily add a dll to your current project.
In your Solution Explorer, right click at the very top line, it'll read something like "Solution 'project_name'(1 project)". On the menu (3 down from the top) there is the option Add, mouse over it and click New Project. This will bring up a new project window. You'll want to choose Class Library from the options, then click Ok. This will add the dll project to your application.
Once it's all added and such, back in the Solution Explorer you'll see both projects, but you need to reference the new dll now. Right click on the name of your project and find and click Add Reference. This window might take a few minutes to load, once it does, look for the tab labeled Projects. The project you just added should be listed there. Select it and click Ok.
That should add the dll and have it built alongside your application when you go to run/build/deploy it.
I hope this is what you're asking, apologies if it's not.
If anyone has or knows of a tutorial for this (with images), it would be highly appreciated.