How can I draw a straight line between two UIImageViews and have the line “refresh” if one of the views is moved. I assume I’ll have to use NSNotificationCenter, but other then that I’m a bit stuck.
Thanks for your help!!!
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How can I draw a straight line between two UIImageViews and have the line “refresh” if one of the views is moved. I assume I’ll have to use NSNotificationCenter, but other then that I’m a bit stuck.
Thanks for your help!!!
A good way to do this would be to use KVO (Key-Value Obverving).
If you use KVO to watch for changes in the bounds (or frame) of the views, you will get notified about position changes, at which point you can (re-)render a line on the display.
More about KVO: https://stackoverflow.com/questions/1470167/is-there-any-tutorial-out-there-on-key-value-coding-and-key-value-observing
As for rendering a line: one often used technique is to write a subclass of UIView in which you override the drawRect method and draw a line using Core Graphics. See this question: How do I draw a line on the iPhone?