常用小问题

1.获得资源文件路径:

//- (NSString *)pathForResource:(NSString *)name ofType:(NSString *)extension

NSString *path=[[ NSBundle mainBundle ] pathForResource :@"bk"  ofType : @"png" ];

2.得到应用程序代理:

[[ UIApplication sharedApplication ] delegate];

3.应用程序大小:

[[UIScreen mainScreen] applicationFrame];