How to set a rotation point for a UIImageView help?

[Kenenth]

I am creating an app in witch a big part of the game is being able to rotate a UIImageview that is a gun barrel. It is rotated by the user interacting with the slider. The slider value is from -.50 to .50. I multiply the slider value by 180 to get the degrees (from 0 to 180 degrees) and then rotate my image based on that value. But, the Image is only being rotated around the center, like this:
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* <-- rotation point
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But i need the rotation point to be on the bottom, like this:


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* <-- rotation point



Please tell me how I can set the rotation point. Im 12 so try to keep it simple. Thanks!

[MatthewD]

Check out the anchorPoint property for the view's layer.

view.layer.anchorPoint = CGPointMake(0.5f, 1.0f);