objective-c - UIButton GIF 背景画像

Question

GIF画像をUIButton画像の背景として使用するにはどうすればよいですか?

        UIImage *img1 = [UIImage imageNamed:@"btn_img1"];
        UIImage *img2 = [UIImage imageNamed:@"btn_img2"];
        UIImage *img3 = [UIImage imageNamed:@"btn_img3"];

        // GIF ImageView
        _btnGIF.imageView.animationImages = [[NSArray alloc] initWithObjects:img1, img2, img3, nil];
        _btnGIF.imageView.animationDuration = 0;
        [_btnGIF.imageView startAnimating];

        //[_btnGIF setBackgroundImage:GIF forState:UIControlStateNormal];