Error解决：Property's synthesized getter follows Cocoa naming convention for returning 'owned'

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mb61c46a7ab1eee 2022-01-10 18:07:01 ©著作权

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在项目中定义了以new开头的textField。结果报错：

先看我的源代码：

#import <UIKit/UIKit.h>

@interface ResetPasswordViewController : UIViewController
@property (weak, nonatomic) IBOutlet UITextField *phoneTextField;
@property (weak, nonatomic) IBOutlet UITextField *oldPasswordTextField;
<span style="color:#FF0000;">@property (weak, nonatomic) IBOutlet UITextField *newPasswordTextField;</span>
@property (weak, nonatomic) IBOutlet UITextField *confirmPasswordTextField;
@property (weak, nonatomic) IBOutlet UINavigationItem *navigationItem;

@end

解决的方法： 最简单的方法是改我们定义属性的名字。不要以new、copy、alloc等关键词开头！！。

y guess is that the compiler version you’re using follows the memory management rules for declared properties, too — more specifically, for declared properties’ accessors:

You take ownership of an object if you create it using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy”.

A property named newTitle, when synthesised, yields a method called -newTitle, hence the warning/error. -newTitle is supposed to be a getter method for the newTitle property, however naming conventions state that a method whose name begins with new returns an object that’s owned by the caller, which is not the case of getter methods.

You can solve this by:

Renaming that property:
@property (strong, nonatomic) NSString *theNewTitle;
Keeping the property name and specifying a getter name that doesn’t begin with one of the special method name prefixes:
@property (strong, nonatomic, getter=theNewTitle) NSString *newTitle;
Keeping both the property name and the getter name, and telling the compiler that, even though the getter name starts with new, it belongs to the none method family as opposed to the new method family:
#ifndef __has_attribute#define __has_attribute(x) 0 // Compatibility with non-clang compilers #endif #if __has_attribute(objc_method_family) #define BV_OBJC_METHOD_FAMILY_NONE __attribute__((objc_method_family(none))) #else #define BV_OBJC_METHOD_FAMILY_NONE #endif @interface ViewController : UIViewController @property (strong, nonatomic) NSString *newTitle; - (NSString *)newTitle BV_OBJC_METHOD_FAMILY_NONE; @endNote that even though this solution allows you to keep newTitle as both the property name and the getter name, having a method called -newTitle that doesn’t return an object owned by the caller can be confusing for other people reading your code.