UIView 用法示例

  [UIView beginAnimations:nil context:nil];
  [UIView setAnimationDelay:0.8];
  [UIView setAnimationDuration:6.5];
  [UIView setAnimationCurve:UIViewAnimationCurveLinear];
  [UIView setAnimationWillStartSelector:@selector(yourmethod)];
  [UIView setAnimationDidStopSelector:@selector(yourmethod)];
  [UIView setAnimationDelegate:self];
  [_backgroundImage setCenter:CGPointMake(20,650)];
   [UIView commitAnimations];