NSLog(@"%@:%@:%d",self.class,NSStringFromSelector(_cmd),__LINE__);
NSLog(@"%@",[NSString stringWithFormat:@"%s - Line %d :",__FUNCTION__,__LINE__]);
打印如下：
2015-06-24 13:48:25.578 testCodata2[2350:63805] ViewController:viewDidLoad:29
2015-06-24 13:48:25.589 testCodata2[2350:63805] -[ViewController viewDidLoad] - Line 31 :