UIView animation cancels previous animation?

I have an NSTIMER that counts the time开发者_C百科, and on t = 10, it fires an animation but during that time it might happen that another animation is running. This causes the previously running animation to cut off.

Any idea? i thought UIVIEW animations were ran in diff threads. I cannot use a willstop selector here since t = 10 might happen while another animation is running and might not have ended yet.

You need to call [UIView setAnimationBeginsFromCurrentState:YES];