iOS設定UIButton圖片在上文字在下

寫app的UI時總會碰到一個按鈕下方還會有文字提示，以往我的做法都是UIButton設定為圖片，在下方再新增一個UILabel，後來發現有一個更簡單的方法，直接設定UIButton的圖片加文字，並調整位置。程式碼如下

UIButton *myButton =  [[UIButton alloc] init];
myButton.titleLabel.backgroundColor = [UIColor greenColor];
CGSize imageSize = myButton.imageView.frame.size;
CGSize titleSize = myButton.titleLabel.frame.size;
CGSize textSize = [myButton.titleLabel.text myButton.titleLabel.font]; 
CGSize frameSize = CGSizeMake(ceilf(textSize.width), ceilf(textSize.height));
if (titleSize.width + 0.5 < frameSize.width) {
    titleSize.width = frameSize.width;
}
CGFloat totalHeight = (imageSize.height + titleSize.height + spacing);
myButton.imageEdgeInsets = UIEdgeInsetsMake(- (totalHeight - imageSize.height), 0.0, 0.0, - titleSize.width);
myButton.titleEdgeInsets = UIEdgeInsetsMake(0, - imageSize.width, - (totalHeight - titleSize.height), 0);