I'm trying to add control to another TabItem on design view, but I can only see the first TabItem with all the controls I previously added and at the moment I can only add controls by hard coding on code view window, therefore I have to compile the program in order to see the results of the controls added by hard coding.
Any help would be appreciated.
As SnOrfus says, apparently it may create some conflict when you start doing some hard coding although it is uncommon thing what happen to you as I can work on the design view creating tab control, tab items and manipulating trough the design view.
My recommendation would be, 1.- Check if you have install the later Service Pack for Visual Studio. (Check for updates for VS2008) 2.- Start over your design from fresh, working only on design view. 3.- Try to use "Wrappanel" or "stackPanel" instead of canvas or grid inside of tabitem ( that will help you with the layout).
If you use WrapPanel you may need to look at the behaviour of scrolling and wrapping its content.
Hope this helps.