ios - 如何根据 NSString 日期键在 NSDictionary 下方排序？

Question

如何根据 NSString 格式的日期键对下面的 NSSDictionary 进行排序？

Printing description of dictMessageWithDate:
{
    "06:10:2015" =     (
        "<ChatMessage: 0x78e108c0>"
    );
    "25:09:2015" =     (
        "<ChatMessage: 0x78fe8740>",
        "<ChatMessage: 0x78ff5e50>",
        "<ChatMessage: 0x78ff58b0>",
        "<ChatMessage: 0x790205c0>",
        "<ChatMessage: 0x7901ee00>",
        "<ChatMessage: 0x79025990>",
        "<ChatMessage: 0x7901f190>",
        "<ChatMessage: 0x78faab50>",
        "<ChatMessage: 0x78ff8ff0>",
        "<ChatMessage: 0x78ff9860>",
        "<ChatMessage: 0x78ffa1c0>",
        "<ChatMessage: 0x78ffa490>",
        "<ChatMessage: 0x78ff6810>",
        "<ChatMessage: 0x78f98720>",
        "<ChatMessage: 0x78f99790>",
        "<ChatMessage: 0x78f42eb0>"
    );
    "28:09:2015" =     (
        "<ChatMessage: 0x78ffad90>"
    );
    "29:09:2015" =     (
        "<ChatMessage: 0x78ff1de0>",
        "<ChatMessage: 0x78edad20>",
        "<ChatMessage: 0x78e7a9d0>"
    );
    "30:09:2015" =     (
        "<ChatMessage: 0x78ec3ac0>"
    );
}

Answer 1

我建议重组:

1. 在ChatMessage (@property NSDate *dateSent) 上放置一个date sent 属性。它应该已经有了一个，因为这是消息的一个重要属性。
2. 将聊天消息保存在 NSArray 中，这是一个有序集合类。

3. 像这样对聊天消息进行排序:

   NSSortDescriptor *dateDescriptor = [NSSortDescriptor
                                    sortDescriptorWithKey:@"dateSent" 
                                                ascending:YES];
   NSArray *sorted = [unsorted
        sortedArrayUsingDescriptors:@[dateDescriptor]];