objc_setAssociatedObject在iPhone模拟器中不可用 [英] objc_setAssociatedObject unavailable in iPhone simulator

问题描述

在3.1 SDk中，Apple添加了对关联对象的支持。

但是，模拟器不会编译包含对objc_setAssociatedObject，objc_getAssociatedObject等引用的代码。 （未声明的错误）

这附近有没有？我可以让iPhone模拟器编译这段代码吗？

>

错误提交：
rdar：// 7477326

解决方案

快速和肮脏的解决方法（大部分未测试，可能是错误的）：

  #if TARGET_IPHONE_SIMULATOR 
 
 #import < objc / runtime.h> 
 
枚举{
 OBJC_ASSOCIATION_ASSIGN = 0，
 OBJC_ASSOCIATION_RETAIN_NONATOMIC = 1，
 OBJC_ASSOCIATION_COPY_NONATOMIC = 3，
 OBJC_ASSOCIATION_RETAIN = 01401，
 OBJC_ASSOCIATION_COPY = 01403 
}; 
 typedef uintptr_t objc_AssociationPolicy; 
 
 @implementation NSObject（OTAssociatedObjectsSimulator）
 
 static CFMutableDictionaryRef theDictionaries = nil; 
 
 static void Swizzle（Class c，SEL orig，SEL new）//由Mike Ash调用sw 
 {
方法origMethod = class_getInstanceMethod（c，orig）; 
方法newMethod = class_getInstanceMethod（c，new）; 
 if（class_addMethod（c，orig，method_getImplementation（newMethod），method_getTypeEncoding（newMethod）））
 class_replaceMethod（c，new，method_getImplementation（origMethod），method_getTypeEncoding 
 else 
 method_exchangeImplementations（origMethod，newMethod）; 
} 
 
  - （NSMutableDictionary *）otAssociatedObjectsDictionary 
 {
 if（！theDictionaries）
 {
 theDictionaries = CFDictionaryCreateMutable（NULL， NULL，& kCFTypeDictionaryValueCallBacks）; 
 Swizzle（[NSObject类]，@selector（dealloc），@selector（otAssociatedObjectSimulatorDealloc））; 
} 
 
 NSMutableDictionary * dictionary =（id）CFDictionaryGetValue（theDictionaries，self）; 
 if（！dictionary）
 {
 dictionary = [NSMutableDictionary dictionary]; 
 CFDictionaryAddValue（theDictionaries，self，dictionary）; 
} 
 
返回字典; 
} 
 
  - （void）otAssociatedObjectSimulatorDealloc 
 {
 CFDictionaryRemoveValue（the Dictionary，self）; 
 [self otAssociatedObjectSimulatorDealloc]; 
} 
 
 @end 
 
 void objc_setAssociatedObject（id object，void * key，id value，objc_AssociationPolicy policy）
 {
 NSCAssert policy == OBJC_ASSOCIATION_RETAIN_NONATOMIC，@Only OBJC_ASSOCIATION_RETAIN_NONATOMIC supported）; 
 
 [[object otAssociatedObjectsDictionary] setObject：value forKey：[NSValue valueWithPointer：key]]; 
} 
 
 id objc_getAssociatedObject（id object，void * key）
 {
 return [[object otAssociatedObjectsDictionary] objectForKey：[NSValue valueWithPointer：key] 
} 
 
 void objc_removeAssociatedObjects（id object）
 {
 [[object otAssociatedObjectsDictionary] removeAllObjects]; 
} 
 
 #endif 
  

In the 3.1 SDk, Apple added support for associated objects.

However, the simulator will not compile code that includes references to objc_setAssociatedObject, objc_getAssociatedObject, et al. (Undeclared errors)

Is there away around this? Can I make the iPhone simulator compile this code? I would hate to have to do all testing on the device.

---

Update

Bug Filed: rdar://7477326

解决方案

A quick and dirty workaround (largely untested, may be buggy):

#if TARGET_IPHONE_SIMULATOR

#import <objc/runtime.h>

enum {
    OBJC_ASSOCIATION_ASSIGN = 0,
    OBJC_ASSOCIATION_RETAIN_NONATOMIC = 1,
    OBJC_ASSOCIATION_COPY_NONATOMIC = 3,
    OBJC_ASSOCIATION_RETAIN = 01401,
    OBJC_ASSOCIATION_COPY = 01403
};
typedef uintptr_t objc_AssociationPolicy;

@implementation NSObject (OTAssociatedObjectsSimulator)

static CFMutableDictionaryRef theDictionaries = nil;

static void Swizzle(Class c, SEL orig, SEL new) // swizzling by Mike Ash
{
    Method origMethod = class_getInstanceMethod(c, orig);
    Method newMethod = class_getInstanceMethod(c, new);
    if (class_addMethod(c, orig, method_getImplementation(newMethod), method_getTypeEncoding(newMethod)))
        class_replaceMethod(c, new, method_getImplementation(origMethod), method_getTypeEncoding(origMethod));
    else
        method_exchangeImplementations(origMethod, newMethod);
}

- (NSMutableDictionary *)otAssociatedObjectsDictionary
{
    if (!theDictionaries)
    {
        theDictionaries = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
        Swizzle([NSObject class], @selector(dealloc), @selector(otAssociatedObjectSimulatorDealloc));
    }

    NSMutableDictionary *dictionary = (id)CFDictionaryGetValue(theDictionaries, self);
    if (!dictionary)
    {
        dictionary = [NSMutableDictionary dictionary];
        CFDictionaryAddValue(theDictionaries, self, dictionary);
    }

    return dictionary;
}

- (void)otAssociatedObjectSimulatorDealloc
{
    CFDictionaryRemoveValue(theDictionaries, self);
    [self otAssociatedObjectSimulatorDealloc];
}

@end

void objc_setAssociatedObject(id object, void *key, id value, objc_AssociationPolicy policy)
{
    NSCAssert(policy == OBJC_ASSOCIATION_RETAIN_NONATOMIC, @"Only OBJC_ASSOCIATION_RETAIN_NONATOMIC supported");

    [[object otAssociatedObjectsDictionary] setObject:value forKey:[NSValue valueWithPointer:key]];
}

id objc_getAssociatedObject(id object, void *key)
{
    return [[object otAssociatedObjectsDictionary] objectForKey:[NSValue valueWithPointer:key]];
}

void objc_removeAssociatedObjects(id object)
{
    [[object otAssociatedObjectsDictionary] removeAllObjects];
}

#endif

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