正确使用NS_DESIGNATED_INITIALIZER

为什么会提到NS_DESIGNATED_INITIALIZER

最近在清理项目警告，遇到了“Method override for the designated initializer”的警告，全称为：

• Method override for the designated initializer of the superclass '-init' not found 或者
• Method override for the designated initializer of the superclass '-initWithNibName:bundle:' not found。

经排查是因为头文件中出现NS_DESIGNATED_INITIALIZER 声明的初始化方法，如下：

// .h - (instancetype)initWithPurchaseService:(HTLPrepayPurchaseService *)service NS_DESIGNATED_INITIALIZER;

如果用了NS_DESIGNATED_INITIALIZER，那么警告中出现init还是initWithNibName或是其它，取决于你的继承的父类类型：

UIViewController

• Method override for the designated initializer of the superclass '-initWithNibName:bundle:' not found
• Method override for the designated initializer of the superclass '-initWithCoder:' not found

UIView

• Method override for the designated initializer of the superclass '-initWithFrame:' not found
• Method override for the designated initializer of the superclass '-initWithCoder:' not found

NSObject

• Method override for the designated initializer of the superclass '-init' not found