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];