ios - 如何根据键 "id"升序对 NSDictionary 进行排序？

Question

你好这是我从服务器得到的

{
        1 =         {

            "display_name" = "One";
            id = 1;
     };
      2 =         {

            "display_name" = "Two";
            id = 2;
     };
      13 =         {

            "display_name" = "abc";
            id = 13;
     };
      15 =         {

            "display_name" = "aaa";
            id = 15;
     };
     4 =         {

            "display_name" = "ffd";
            id = 4;
     };
      3 =         {

            "display_name" = "abdfdfc";
            id = 3;
     };
      5 =         {

            "display_name" = "aasdfsdfa";
            id = 5;
     };
}

我需要根据“id”对其进行排序，这就是输出结果

期待输出

{
        1 =         {

            "display_name" = "One";
            id = 1;
     };
      2 =         {

            "display_name" = "Two";
            id = 2;
     };
      3 =         {

            "display_name" = "abdfdfc";
            id = 3;
     };
      4 =         {

            "display_name" = "ffd";
            id = 4;
     };
     5 =         {

            "display_name" = "aasdfsdfa";
            id = 5;
     };
      13 =         {

            "display_name" = "abc";
            id = 13;
     };
      15 =         {

            "display_name" = "aaa";
            id = 15;
     };
}

这段代码我已经试过了，但它不起作用

 //vehiclesDictionary   real dictionary
        NSMutableArray *sortedKeys=[[NSMutableArray alloc]init];
         for(NSString *item in [vehiclesDictionary allKeys]){
             [sortedKeys addObject:[NSNumber numberWithInt:[item intValue]]];
         }


         NSArray *sortedKeysArray = [sortedKeys sortedArrayUsingSelector: @selector(compare:)];
         NSLog(@"%@",sortedKeysArray);

         NSMutableDictionary *sortedValues = [[NSMutableDictionary alloc] init];
         for (NSString *key in sortedKeysArray) {
             [sortedValues setValue:[vehiclesDictionary valueForKey:[NSString stringWithFormat:@"%@",key]] forKey:key];
         }

         NSLog(@"%@",sortedValues);

请帮帮我

Answer 1

您不能对 NSDictionary 进行排序，它是一种未排序的集合类型。您需要将键存储在一个数组中并对其进行排序，然后使用它按顺序访问 NSDictionary。

根据您上面的代码，可以修改如下，例如

NSDictionary *dict = [NSDictionary dictionary];

NSArray *sortedKeys = [[dict allKeys] sortedArrayUsingSelector:@selector(compare:)];

for (NSString *key in sortedKeys) {
    NSLog(@"%@", [d objectForKey:key]);

    // Do something with the object here
}

在这里，您可以使用 NSDictionary 传递sortedKeys 数组，并使用sortedKeys 数组按顺序访问您的NSDictionary。

一种更简洁的获取数组的方法，但与上面的结果相同，将使用:

NSDictionary -keysSortedByValueUsingComparator 如图所示 here .