跑马灯效果

  [UIView beginAnimations:@"testAnimation"context:NULL];
    [UIView setAnimationDuration:15.0f];
    [UIView setAnimationCurve:UIViewAnimationCurveLinear];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationRepeatAutoreverses:NO];
    [UIView setAnimationRepeatCount:999999];
    frame = labelShow.frame;
    frame.origin.x = -frame.size.width;
    labelShow.frame = frame;
    [UIView commitAnimations];