我在
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
这个方法里面使用
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[[UIScreen mainScreen] bounds]获取尺寸不对
原文：http://www.cnblogs.com/xuejinhui/p/5047658.html