如何将NSMutableDictionary保存到文档中的文件中？ [英] How to save a NSMutableDictionary into a file in documents?

问题描述

我想将NSMutableDictionary对象的内容保存到文件中。我该怎么做呢 ？我已经知道如何使用NSDictionary对象执行此任务但我不知道如何将此NSMutableDictionary转换/复制到NSDictionary ...除非有一种方法直接将NSMutableDictionary的内容写入文件...我强调NSMutableDictionary对象包含NSDictionary类型的对象。

I would like to save the content of a NSMutableDictionary object to a file. How do I do this ? I already know how to do this task with a NSDictionary object but I don't know how to convert/copy this NSMutableDictionary to a NSDictionary...unless there's a method to write directly the content of NSMutableDictionary to a file...I stress that the NSMutableDictionary object contains objects of NSDictionary type.

Thx用于帮助，

Stephane

推荐答案

NSMutableDictionary 是 NSDictionary的子类：您可以在任何使用 NSDictionary 的地方使用它。从字面上看，只需将对象传递给您现在用于 NSDictionary 的相同代码。

NSMutableDictionary is a subclass of NSDictionary: you can use it anywhere you'd use NSDictionary. Literally, just pass the object through to the same code you use for NSDictionary right now.

更一般感觉，如果您真的需要从 NSMutableDictionary 获得真正不可变的 NSDictionary ，只需调用复制 NSMutableDictionary 。

In a more general sense, if you ever actually need to get a truly immutable NSDictionary from an NSMutableDictionary, just call copy on the NSMutableDictionary.

其他方法包括 [NSDictionary dictionaryWithDictionary：] 或 [NSDictionary alloc] initWithDictionary：] ，这些都基本相同。

Other approaches include [NSDictionary dictionaryWithDictionary:] or [NSDictionary alloc] initWithDictionary:], which all amount to essentially the same thing.

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