1.從xib加載ViewController?
（1）調(diào)用CustomerVC *vc =[[CustomerVC alloc] initWithNibName:@"CustomerVC" bundle:[NSBundle mainBundle]];
會(huì)調(diào)用-(instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
（2）CustomerVC *vc = [[CustomerVC alloc] init];
會(huì)先調(diào)用-(instancetype)init然后調(diào)用-(instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
2.從xib加載View
(1).CustomView *myView = [[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:nil options:nil].lastObject;
不會(huì)調(diào)用init,和initwithframe方法
(2).CustomView *myView = [[CustomView alloc] init];
先調(diào)用init方法->再調(diào)用initwithframe方法
(3).如果在xib中嵌入了CustomView視圖，會(huì)調(diào)用initwithcoder->再調(diào)用awakefromnib方法
