iOS UIButton 设置图片文字垂直排列

后面经过测试，如果button的文字长度变更，会导致图片位置变化，经过多次修改UIEdgeInsets的值也没有达到期望效果，最终采用集成UIButton类，重写layoutSubviews函数实现，特将成果记录一下，以便后续查阅

-( void )layoutSubviews {
    [super layoutSubviews];

    // Center image
    CGPoint center = self.imageView.center;
    center.x = self.frame.size.width/2;
    center.y = self.imageView.frame.size.height/2;
    self.imageView.center = center;

    //Center text
    CGRect newFrame = [self titleLabel].frame;
    newFrame.origin.x = 0;
    newFrame.origin.y = self.imageView.frame.size.height + 5;
    newFrame.size.width = self.frame.size.width;

    self.titleLabel.frame = newFrame;
    self.titleLabel.textAlignment = UITextAlignmentCenter;
}

通过重写，重新设置imageView的Center和titleLabel的Frame解决上述问题。