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];
