通过NSTimer UserInfo传递数据 [英] Passing Data through NSTimer UserInfo

问题描述

我正在尝试通过userInfo传递数据以进行NSTimer调用。做这个的最好方式是什么？我正在尝试使用NSDictionary，当我有Objective-C对象时这很简单，但其他数据呢？我想做这样的事情，它不能正常工作：

I am trying to pass data through userInfo for an NSTimer call. What is the best way to do this? I am trying to use an NSDictionary, this is simple enough when I have Objective-C objects, but what about other data? I want to do something like this, which doesn't work as is:

- (void)play:(SystemSoundID)sound target:(id)target callbackSelector:(SEL)selector
{
    NSLog(@"pause ipod");
    [iPodController pause];
    theSound = sound;

    NSMutableDictionary *cb = [[NSMutableDictionary alloc] init];
    [cb setObject:(id)&sound forKey:@"sound"];
    [cb setObject:target forKey:@"target"];
    [cb setObject:(id)&selector forKey:@"selector"];

    [NSTimer scheduledTimerWithTimeInterval:0
                                     target:self
                                   selector:@selector(notifyPause1:)
                                   userInfo:(id)cb
                                    repeats:NO];
}

推荐答案

你必须包装信息正确进入字典：

You have to wrap the information correctly into the dictionary:

- (void) play:(SystemSoundID)sound target:(id)target callbackSelector:(SEL)selector
{
    NSLog(@"pause ipod");
    [iPodController pause];
    theSound = sound;

    NSMutableDictionary *cb = [[NSMutableDictionary alloc] init];
    [cb setObject:[NSNumber numberWithInt:sound] forKey:@"sound"];
    [cb setObject:target forKey:@"target"];
    [cb setObject:NSStringFromSelector(selector) forKey:@"selector"];

    [NSTimer scheduledTimerWithTimeInterval:0
                                     target:self
                                   selector:@selector(notifyPause1:)
                                   userInfo:cb 
                                     repeats:NO];
    [cb release];

}

在 notifyPause1：，你检索所有东西：

- (void)notifyPause1:(NSTimer *)timer {
    NSDictionary *dict = [timer userInfo];

    SystemSoundID sound = [[dict objectForKey:@"sound"] intValue];
    id target = [dict objectForKey:@"target"];
    SEL selector = NSSelectorFromString([dict objectForKey:@"selector"]);

    // Do whatever...
}

As计时器是一个重复计时器，你不再需要字典，所以你可以释放它。

As the timer is a repeating timer, you do not need the dictionary anymore, so you can release it.

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