问题描述
我是否误解绑定的问题？我绑定（一个NSArrayController的内容）到NSDictionary的allValues数组，并认为它是空的。我绑定到一个随机对象的属性，我已经设置为相同的NSDictionary的allValues数组，它工作正常。
Am I misunderstanding something about bindings? I bind (an NSArrayController's content) to an NSDictionary's "allValues" array, and it thinks it's empty. I bind to a random object with a property that I've set to be that same NSDictionary's "allValues" array, and it works fine.
这是预期的行为，我做错了什么？此外，如果这是预期的，什么是处理这种标准的方法？
Is this expected behavior, or am I doing something wrong? Furthermore, if this is expected, what is the standard way to deal with this? Making relatively purposeless objects just to hold arrays in properties so I can bind to them seems ugly.
推荐答案
绑定到 @allValues表示向字典发送 -valueForKey：@allValues消息。然后，字典通过查找 -objectForKey：@allValues来解释它，这不是你在这种情况下的。
Binding to @"allValues" means the dictionary is sent a -valueForKey:@"allValues" message. The dictionary then interprets that by looking up -objectForKey:@"allValues" which is not what you are after in this case.
尝试绑定到 @@ allValues（参见 - [NSDictionary valueForKey：] 更多详情）
Try binding to @"@allValues" instead (see the -[NSDictionary valueForKey:] docs for more details)
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