iOS button 图片居右文字居左

[openBtn setTitleEdgeInsets:UIEdgeInsetsMake(0,-openBtn.imageView.bounds.size.width, 0, openBtn.imageView.bounds.size.width)];

[openBtn setImageEdgeInsets:UIEdgeInsetsMake(0, openBtn.titleLabel.bounds.size.width, 0, -openBtn.titleLabel.bounds.size.width)];