2d editor in c#

[Joao Barros]

I know almost nothing about c#, although I know C++ quite well (I
think ;-)) and some Java.
As it seems c# is a good alternative to Java, I am trying to decide if
c# is a good option to the following:

- A simple 2d graphical editor allowing the drawing of rectangles,
circles, text objects, and arcs (lines with arrow points) between
them.
- Undo/redo,copy/paste and the usual related stuff
- Connectors between objects: for example, when I drag a rectangle I
want the connecting arcs to be dragged together with it.

What is the easiest way to achieve this in C#? Is there any code
example of something similar available? Some free library?

In Java there are some interesting code available. I specially liked
jhotdraw as it does what I need. Yet, if I can do it quickly in c# I
would like to know.

Thanks a lot in advance

Joao

 

[Vijaye Raji]

It's very easy to write one yourself.

I'd proceed with creating a Control class and derive all the specialized
objects (like rectanlge, circle, etc) from it. Then, I'd have a Designer
class that would host all the controls. The Drawing of the controls will be
orchestrated by the Designer by passing a Graphics object to each of the
embedded controls.

This way, you could implement project save/load very easily through
available Serializers.

For Undo & Redo, you can write a helper class that will record every action
on the designer. You could go one step further and provide transactions on
your UndoRedoHelper class. THis way, you can handle multiple
delete/copy/paste in one shot.

With some smart use of attributes (like Browsable, Category, Description,
etc.), you can add a property Grid to your main form that will hold the
currently selected object and you can change the objects properties (like
size, location, radius - if it's a circle, etc.) from the PropertyGrid
window.

Hope this helps.
vJ

 

[Bob Powell [MVP]]

You might want to take a look atthe GDI+ FAQ and the article on
"Manipulating Graphics" which delves into this subject a bit.

--
Bob Powell [MVP]
C#, System.Drawing

The November edition of Well Formed is now available.
Learn how to create Shell Extensions in managed code.
http://www.bobpowell.net/currentissue.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/gdiplus_faq.htm

Read my Blog at http://bobpowelldotnet.blogspot.com

 

[John Kordyback]

Check out the link:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/designsurface.asp

The example is in VB, but it isn't difficult to convert.

/qb

 

[Francois Vanderseypen]

The Netron Project is open source and has all you need to make graphical editors:
http://netron.sourceforge.net