ios – 核心数据：语句仍然有效

我创建了一种基于线程名称(1个线程= 1上下文)创建不同上下文的机制.

#include <pthread.h>
...

    mach_port_t threadID = pthread_mach_thread_np(pthread_self());
    Nsstring *threadName = [Nsstring stringWithFormat:@"%x",threadID];
    NSManagedobjectContext *context = [singleton.threadsContexts objectForKey:threadName];
    if (!context) {
        NSLog(@"Creating managed context for thread named '%@'",threadName);
        context = [[NSManagedobjectContext alloc] init];
        [context setPersistentStoreCoordinator:[singleton.managedobjectContext persistentStoreCoordinator]];

        //initialize dictionary in your singleton if it as not been yet
        if(!singleton.threadsContexts)
        {
            singleton.threadsContexts = [NSMutableDictionary new];
        }
        [singleton.threadsContexts setobject:context forKey:threadName];
    }

    return result;

然后,当我需要一个后台线程中的托管对象的完整版本时,我将获得专用于此线程的对象的副本：

NSManagedobjectModel *myNewObject = [myBackgroundContext objectWithID:[myObject objectID]];

希望这个答案有所帮助.