Question

我有一个NSArray包含从服务器获取的多个NSDictionary，我希望迭代NSDictionary中key's value个"id"中的每个NSMutableArray，然后将它们添加到"for loop"。我使用NSMutableArray来实现此功能，但Xcode debug area登录NSDictionary的结果非常奇怪且不正确。

这是NSArray中每//Get the dictionary that included item ids. NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:&error]; //Create the array add item id objects. NSMutableArray *itemIds = [NSMutableArray array]; //Fetching item ids in dictionary array. NSArray *itemIdsDictionary = dictionary[@"itemRefs"]; NSLog(@"%i", [itemIdsDictionary count]);//Have valid dictionary. for(int i = 0; i < [itemIdsDictionary count]; i++) { NSString *aId = (itemIdsDictionary[i])[@"id"]; [itemIds addObject:aId]; NSLog(@"%@", itemIds); NSLog(@"%@", aId); }次迭代的代码。

NSMutableArray

Xcode degug area登录2013-07-04 22:55:26.053 Readable[3222:c07] 5 2013-07-04 22:55:26.053 Readable[3222:c07] ( 51d58c198e49d061db0011e3 ) 2013-07-04 22:55:26.054 Readable[3222:c07] ( 51d58c198e49d061db0011e3, 51d58c198e49d061db0011e4 ) 2013-07-04 22:55:26.054 Readable[3222:c07] ( 51d58c198e49d061db0011e3, 51d58c198e49d061db0011e4, 51d5745982d493d61500e706 ) 2013-07-04 22:55:26.054 Readable[3222:c07] ( 51d58c198e49d061db0011e3, 51d58c198e49d061db0011e4, 51d5745982d493d61500e706, 51d5745982d493d61500e707 ) 2013-07-04 22:55:26.054 Readable[3222:c07] ( 51d58c198e49d061db0011e3, 51d58c198e49d061db0011e4, 51d5745982d493d61500e706, 51d5745982d493d61500e707, 51d55fb04de3837bf3006e83 )是：

{{1}}

真的希望有人可以帮我解决这个问题，这是我自己的应用中非常重要的阶段。感谢!!!!!!

Answer 1

试试这个 -

    for(int i = 0; i < [itemIdsDictionary count]; i++)
    {
         NSDictionary *dictionary = [itemIdsDictionary objectAtIndex:i];
         [itemIds addObject:[dictionary objectForKey:@"id"]]; 
    }

    NSLog(@"itemIds : %@",itemIds);

Answer 2

尝试

for (NSDictionary *dict in itemIdsDictionary)
    [itemIds addObject:[dict valueForKey@"id"]];

Answer 3

如果你给出了字典的结构，那也会有所帮助。从Web服务返回什么密钥？等。

//Get the dictionary that included item ids.
NSDictionary *dictionary = [NSDictionary dictionary];

//Create the array to hold the ID's
NSMutableArray *itemIds = [NSMutableArray array];

//Fetching item ids in dictionary array.
NSArray *itemIdsDictionary = dictionary[@"itemRefs"];

[itemIdsDictionary enumerateObjectsUsingBlock:^(NSDictionary *dict, NSUInteger idx, BOOL *stop) {
    [itemIds addObject:[dict objectForKey:@"id"]];
}];

以下是我认为你要做的事情的一个例子。

如果要确保只有一个ID条目，即使您的字典中有重复的Web服务，您也可以使用NSMutableSet来阻止它。以下是两者的例子。

//This is just an array to hold the dictionaries that you should get from the web service
NSMutableArray *arrayOfDictionariesFromWebService = [NSMutableArray array];

//Make some fake data for the example
for (int i = 0; i < 5; ++i)
{
    //Make a dictionary with a value for the key id
    NSDictionary *dictionary = @{@"id" : [NSString stringWithFormat:@"ID%d", i]};

    //Add it to the array
    [arrayOfDictionariesFromWebService addObject:dictionary];
}

//Add a duplicate item to show example of using a set
NSDictionary *duplicateObject = @{@"id" : @"ID0"};
[arrayOfDictionariesFromWebService addObject:duplicateObject];

//Create an array and a set to hold the ID's
NSMutableArray *itemIds = [NSMutableArray array];
NSMutableSet *setOfItemIds = [NSMutableSet set];

//Enumerate through the array of dictionaries to pull out the ID from the dictionary and add it to the array and set of IDs
[arrayOfDictionariesFromWebService enumerateObjectsUsingBlock:^(NSDictionary *dict, NSUInteger idx, BOOL *stop) {
    [itemIds addObject:[dict objectForKey:@"id"]];
    [setOfItemIds addObject:[dict objectForKey:@"id"]];
}];

//If you want to sort your ID's you can sort it using sortedArrayUsingDescriptors
NSArray *sortedArrayOfItemIDs = [[setOfItemIds allObjects] sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES]]];

//Log out the result
NSLog(@"Array of ID's \n%@", itemIds);
NSLog(@"Array of ID's from the set \n%@", [setOfItemIds allObjects]);
NSLog(@"Sorted array of ID's from the set \n%@", sortedArrayOfItemIDs);

控制台应如下所示。

2013-07-10 09:04:40.824 STC Companion[574:c07] Array of ID's 
(
    ID0,
    ID1,
    ID2,
    ID3,
    ID4,
    ID0
)
2013-07-10 09:04:40.825 STC Companion[574:c07] Array of ID's from the set 
(
    ID2,
    ID3,
    ID0,
    ID4,
    ID1
}
2013-07-10 09:13:08.063 STC Companion[886:c07] Sorted array of ID's from the set 
(
    ID0,
    ID1,
    ID2,
    ID3,
    ID4
)

如何迭代多个NSDictionary的关键值之一，并将它们添加到NSMutableArray？

3 个答案: