按钮,图片边缘有锯齿

closeBtn.layer.shouldRasterize = YES;
closeBtn.layer.rasterizationScale = [UIScreen mainScreen].scale;

http://www.cocoachina.com/bbs/read.php?tid-1678039.html

【推广】免费学中医，健康全家人

原文地址：https://www.cnblogs.com/tufei7/p/8289648.html