如何使用图片的宽度和高度给UIButton 复制宽高

1. 当你的UIButton 设置的是背景图片的时候，使用"currentBackgroundImage" 来获取 这个背景图片的宽高。

比如:

 UIButton *publishButton = [UIButton buttonWithType:UIButtonTypeCustom];
 [publishButton setBackgroundImage:[UIImage imageNamed:@"tabBar_publish_icon"] forState:UIControlStateNormal];
 [publishButton setBackgroundImage:[UIImage imageNamed:@"tabBar_publish_click_icon"] forState:UIControlStateHighlighted];
        [self addSubview:publishButton];



// 设置发布按钮的frame
    self.publishButton.bounds = CGRectMake(0, 0, self.publishButton.currentBackgroundImage.size.width, self.publishButton.currentBackgroundImage.size.height);
    self.publishButton.center = CGPointMake(self.frame.size.width * 0.5, self.frame.size.height * 0.5);

2. 当你的UIButton 使用的是图片的时候，使用“currentImage”，来获取图片的宽高，给 按钮赋值款宽高。

   self.publishButton.bounds = CGRectMake(0, 0, self.publishButton.currentImage.size.width, self.publishButtoncurrentImage.size.height);