新建一个UIButton的category
.h
@interface UIButton (QXTitleInCenter) -(instancetype)init; @end
.m
@implementation UIButton (QXTitleInCenter)
-(instancetype)init{
self = [super init];
self.contentEdgeInsets = UIEdgeInsetsMake(-(self.intrinsicContentSize.height) * 0.18（调节文字上下高度的，数值越大文字越靠上方）,0, 0, 0);
return self;
}
@end
然后引入这个category，直接用UIButton就OK了
原文：http://www.cnblogs.com/ansyxpf/p/6117247.html