I have the following:

A MainWindow;

with Children on the MainGrid in the MainWindow:

• ContentControl, displays the main content of the program and has a taskbar at the bottom for user interaction
• AddContentControl, shall be started via ContentControl, a control that allows the user to add content to the ContentControl
• TakePictureControl, shall be started from AddContentControl, allows the user to take a picture via webcam
• CropControl, shall be started from TakePictureControl after the Picture was taken, because the image has to be square
• SettingsControl, shall be started from ContentControl, allows to change the settings of the program

So basically I have the following hierarchy:
MainWindow<-MainGrid<-The five controls, only one visible at a time

Since controls are childs of the MainGrid/Window, I can’t access the initialized objects of the control.

What I want is the following:

• Stay in one window
• access a control from another control
• pass arguments to a control from another control (e.g. image from TakePhotoControl to CropControl)
• code that is easy to understand and object oriented

What I had earlier was that I did not encapsulate the controls, so I had the main logic in the MainWindow.xaml.cs and all UI elements sitting directly on the MainGrid. Positive was that I could access everything I wanted. Negative is that this was horrible to read (and it will get worse), not comfortable to edit, not object oriented and barely reusable.

How do I solve my issue?