How to speed up my vb.net application?

Abdallah Alsayed asked:

…but how to use thread and cross-thread invocation?

You cannot call anything related to UI from non-UI thread. Instead, you need to use the method Invoke or BeginInvoke of System.Windows.Threading.Dispatcher (for both Forms or WPF) or System.Windows.Forms.Control (Forms only).

You will find detailed explanation of how it works and code samples in my past answers:
Control.Invoke() vs. Control.BeginInvoke()[^],
Problem with Treeview Scanner And MD5[^].

See also more references on threading:
How to get a keydown event to operate on a different thread in vb.net[^],
Control events not firing after enable disable + multithreading[^].

Basically, in your second, non-UI thread, you should work only with data representing graphics. The main, UI thread, should only render the same data. You need to synchronize this data between threads. To render data, override the method System.Windows.Control.OnPaint of some control. It can be a custom control. To fight flicker effectively, use double buffering (please see control's options). When the data is modified in the second thread (call it "scenario thread"), simply invoke some delegate which calls Control.Invalidate on the rendering control. It will push WM_PAINT Windows message, so your OnPaint handler will be called. With updated data. This way, your animation will be pushed onto the rendering system.

You can also call one of the Invalidate methods with parameters, to render just the part of the scene and improve performance on the parts of the scene where the data was not modified by the animation (you will need to specify a Rectangle or Region for update. If you sequentially quickly invalidate several times with different subsets of the scene points, the involved regions will be merged before they reach the rendering.

This all gives you pretty good performance.

But even better performance can be achieved with WPF, because it is based on fast DirectX.

Please also see my past answers:
Drawing Lines between mdi child forms[^],
capture the drawing on a panel[^],
What kind of playful method is Paint? (DataGridViewImageCell.Paint(...))[^].

—SA

It isn't possible to answer this question as we know nothing about what your app does nor how to implemented things, nor exactly what you mean by "poor performance".

For an editor, I highly doubt that XNA/DirectX is going to give you any benefit at all. On the surface it sounds as though something just isn't implemented correctly and changing out the entire graphics library isn't going to fix that.

Abdallah Alsayed asked:

…is it possible to make my WPF app style like Office 2013 or Visual Studio 2012?

It's apparently possible: if Microsoft did it, you should be able to do it, too.

To tell you more, there is even a good open-source ready-to-use solution, if we can talk about Visual Studio application design. It's called Avalon dock:
http://avalondock.codeplex.com/[^],
with detailed documentation and tutorials: http://avalondock.codeplex.com/documentation[^].

This library closely reproduces the features and style of Visual Studio. It is used in alternative open-source IDE called SharpDevelop:
http://en.wikipedia.org/wiki/SharpDevelop[^],
http://www.icsharpcode.net/OpenSource/SD/Default.aspx[^].

In principle, you can download the whole SharpDevelop and find all parts needed to build the IDE. There is also Avalon Edit, with syntax highlighting for any language, code outlining, and, again, everything the development of Studio-like IDE may need. Those are all independent components.

Besides, there are articles and tutorials on CodeProject:
AvalonDock [2.0] Tutorial Part 1 - Adding a Tool Window[^],
AvalonDock [2.0] Tutorial Part 2 - Adding a Start Page[^],
AvalonDock and MVVM[^].

Enjoy,

—SA