实现一个view从顶部移到底部的动画 and 将RGB值转化为颜色

@interface TimingCurveViewController : UIViewController {
  IBOutlet UIImageView *basketBall;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

  [UIView beginAnimations:@"movement" context:nil];
  [UIView setAnimationCurve:UIViewAnimationCurveEaseIn]; //<label id="code.timingcurve.easeIn"/>
  [UIView setAnimationDuration:1.0f];
  [UIView setAnimationRepeatCount:3];
  [UIView setAnimationRepeatAutoreverses:YES];
  CGPoint center = basketBall.center;
  if(center.y > 85.0f) {
    center.y -= 295.0f;
    basketBall.center = center;
  } else {
    center.y += 295.0f;
    basketBall.center = center;
  }
  [UIView commitAnimations];

}

- (void)viewDidLoad{
    [super viewDidLoad];
    self.view.backgroundColor = [self colorWithRGBHexString:@"#abcdef"];
}

- (UIColor *)colorWithRGBHexString:(NSString *)rgbColor{
    NSString *cString = rgbColor;
    
    //去除空格并大写NSCharacterSetwhitespaceAndNewlineCharacterSet
    
    cString = [[cString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    
    if ([cString length] < 6) {
        
        //返回默认颜色
        
        return [UIColor redColor];
        
    }
    
    if ([cString hasPrefix:@"0x"]) {
        
        cString = [cString substringFromIndex:2];
        
    }else if ([cString hasPrefix:@"#"]){
        
        cString = [cString substringFromIndex:1];
        
    }
    
    if ([cString length] != 6) {
        
        //返回默认颜色
        
        return [UIColor redColor];
        
    }
    
    NSRange range;
    
    range.length = 2;
    
    range.location = 0;
    
    NSString *rString = [cString substringWithRange:range];
    
    range.location = 2;
    
    NSString *gString = [cString substringWithRange:range];
    
    range.location = 4;
    
    NSString *bString = [cString substringWithRange:range];
    
    
    
    unsigned int r,g,b;
    
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    
    [[NSScanner scannerWithString:bString] scanHexInt:&b];
    
    
    
    return [UIColor colorWithRed:(float)r/255.0 green:(float)g/255.0 blue:(float)b/255.0 alpha:1.0f];
}