ios – Objective-C警告未找到超类“-init”的指定的初始化程序的方法覆盖

The rules for designated initialisers are complex and I’m going to bounce you to the docs for the general case. CurIoUsly,I’ve found the best explanation of this to be the “Initialization” section of The Swift Programming Language,because the same concepts apply to both Swift and Objective-C.
In your specific case you should override -init and have it fail at runtime. You should also tag it in your header with NS_UNAVAILABLE which will allow the compiler to catch this in the typical case.
The above applies because your class can’t possibly operate without a Model,and thus you can’t reasonably implement -init in any useful way. If you Could,you should. For example,if you were creating your own string object,it would make sense for it to implement -init by calling super and then initialising the string to the empty string.

在.h文件中：

@interface MyClass : NSObject  
- (instancetype)init NS_UNAVAILABLE;  

@end

在.m文件中：

@interface MyClass ()  
- (instancetype)init NS_DESIGNATED_INITIALIZER;  
@end  

@implementation MyClass  
 - (instancetype)init { @throw nil; }  

@end