change the portrait to landscape and vice versa

I am new to iphone. I want change the view from portrait to landscape and vise versa depends upon device view position. In my app, I am using different kinds views, view controllers, table view controller, web view and so on. For achieve that where i want to put 开发者_运维百科the shouldAutorotateToInterfaceOrientation method? is it necessary to put all the .m class file? or enough to put any one .m file? else what i want to do? please any one give soln.

Note: In landscape view, not able to set the size for whole device view.

shouldAutorotateToInterfaceOrientation: should be included in any view controller classes that you would like to be able to rotate.