Changes

Double click on the draw2DViewController.xib file so that it loads into the Interface Builder tool and select the UIView component in the View window. Display the Identity Inspector (Tools -> Identity Inspector or press the Command+4 key combination) and change the Class setting from UIView to our new class named draw2D:

[[Image:iphone_draw_2d_uiview_class_change.jpg|Changing the base class of a UIView component]]