今天在使用协议的过程中。偶然发现这样使用
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@interface
AppDelegate (){ id<chatdelegate>
testdelegate;}@property
(nonatomic , assign) id<chatdelegate> testdelegate;@end@implementation
AppDelegate@synthesize
testdelegate;</chatdelegate></chatdelegate> |
会报错：
Existing instance variable 'delegate' for property 'delegate' with assign attribute must beunsafe unretained
改动成：
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@interface
AppDelegate (){ __unsafe_unretained
id<chatdelegate> testdelegate;}@property
(nonatomic , assign) id<chatdelegate> testdelegate;@end@implementation
AppDelegate@synthesize
testdelegate;</chatdelegate></chatdelegate> |
就好了，这仅仅是为了相容iOS4下面的版本号