//#define ScreenW 320 //#define ScreenH 480 #define ScreenW [UIScreen mainScreen].bounds.size.width #define ScreenH [UIScreen mainScreen].bounds.size.height // 创建一个显示在屏幕右下角的按钮 CGFloat buttonW = 100; CGFloat buttonH = 50; button.frame = CGRectMake(ScreenW - buttonW, ScreenH - buttonH, buttonW, buttonH);
原文：http://www.cnblogs.com/HMJ-29/p/4758675.html