自定义UIbutton的样式

1.继承自UIButton

2.重写这两个方法:

-(CGRect)titleRectForContentRect:(CGRect)contentRect
{
CGFloat titleY = contentRect.size.height *0.6;
CGFloat titleW = contentRect.size.width;
CGFloat titleH = contentRect.size.height - titleY;
return CGRectMake(0, titleY, titleW, titleH);
}

-(CGRect)imageRectForContentRect:(CGRect)contentRect
{
CGFloat imageW = CGRectGetWidth(contentRect);
CGFloat imageH = contentRect.size.height * 0.6;
return CGRectMake(0, 0, imageW, imageH);
}