部署目标是10.6,因此需要手动内存管理。 该集合应该负责保留/释放 GCD 对象。
我相信 CFDictionary 的 CFArray 的自定义回调会有所帮助,但是我正在寻找一个简单的、经过充分测试的解决方案
最佳答案
回调和集合创建非常简单:
static const void * dispatchObjectRetainCallBack(CFAllocatorRef allocator, const void *value)
{
if (value) {
dispatch_retain(value);
}
return value;
}
static void dispatchObjectReleaseCallBack(CFAllocatorRef allocator, const void *value)
{
if (value) {
dispatch_release(value);
}
}
CFMutableArrayRef CreateDispatchHoldingArray()
{
CFArrayCallBacks callBacks = {
0,
dispatchObjectRetainCallBack,
dispatchObjectReleaseCallBack,
NULL,
NULL
};
return CFArrayCreateMutable(kCFAllocatorDefault, 0, &callBacks);
}
CFMutableDictionaryRef CreateDispatchHoldingDictionary()
{
CFDictionaryValueCallBacks valueCallBacks = {
0,
dispatchObjectRetainCallBack,
dispatchObjectReleaseCallBack,
NULL,
NULL
};
return CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &valueCallBacks);
}
稍微棘手的部分是将 dispatch_object_t
放入和取出集合。您不能简单地将 dispatch_object_t
类型的变量转换为 void *
,因为 dispatch_object_t
是联合的 typedef。编译器报错:
Operand of type 'dispatch_object_t' where arithmetic or pointer type is required
您必须遍历 dispatch_object_t
内的联合类型之一,如下所示:
void AddDispatchObjectToArray(CFMutableArrayRef array, dispatch_object_t obj)
{
void* voidPtrObj = obj._do;
CFArrayAppendValue(array, voidPtrObj);
}
dispatch_object_t GetDispatchObjectAtIndex(CFMutableArrayRef array, CFIndex index)
{
dispatch_object_t result;
result._do = (struct dispatch_object_s *)CFArrayGetValueAtIndex(array, index);
return result;
}
关于cocoa - 如何将 GCD 对象放入 CF 集合(CFArray、CFDictionary)中?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14147565/