自定义一个UIButton

#import "TabBarButton.h"

@implementation TabBarButton

- (CGRect)imageRectForContentRect:(CGRect)contentRect
{
CGFloat imageW = contentRect.size.width;
CGFloat imageH = contentRect.size.height * 0.6; //按钮图标占据内容的比例为0.6
return CGRectMake(0, 0, imageW, imageH);
}
- (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);
}

@end