ios - 根据 NSString 值的匹配从 NSMutableDictionary 中删除条目

Question

在对 Instagram API 进行网络调用后，我得到了一个带有以下键/值结构的 responseDictionary NSDictionary 委托(delegate):

{
data =     (
            {
        bio = "Los Angeles/Orange County Realtor\U00ae \n\U6d1b\U6749\U77f6\U623f\U5730\U4ea7\U7ecf\U7eaa\U4eba\nCall/Text/WhatsApp: (310) 717-1321\nEmail: Jxxxcom\nWeChat (\U5fae\U4fe1): xx";
        "full_name" = "xx yy (\U7530\U4f73\U6dfc) Rx Realty";
        id = 25354408;
        "profile_picture" = "http://scontent-a.cdninstagram.com/hphotos-xpa1/outbound-distillery/t0.0-20/OBPTH/profiles/profile_xxx_75sq_1391378894.jpg";
        username = jxxi;
        website = "http://www.Jxghty.com";
    },

profile_picture 键通常有一个包含 anonymousUser 的 NSString 值(对于没有设置任何个人资料图片的用户)。

我希望从我的 responseDictionary 中删除这些条目，如下所示:

        //Create mutable copy of IG responseDictionary
        NSMutableDictionary *dictCleanAvatars = [responseDictionary mutableCopy];
        NSLog(@"Log dictCleanAvatars after mutableCopy IG response: %@", dictCleanAvatars);

        NSArray *keys = [dictCleanAvatars allKeys]; //get all the keys
        NSUInteger k2 = [dictCleanAvatars count];
        NSLog(@"k2 in dictCleanAvatars before cleanup is: %lu", (unsigned long)k2);

        for (int i = 0; i<k2; i++)
        {

            if ([[dictCleanAvatars objectForKey:[keys objectAtIndex:i]] isKindOfClass:[NSString class]])
            {
                //if its an NSString - don't want an exception if its another type of object
                NSLog(@"Yes, objectAtIndex:i us Kind ofClass NSString for i = %d", i);

                if ([[dictCleanAvatars objectForKey:[keys objectAtIndex:i]] rangeOfString:@"anonymousUser"].location != NSNotFound)
                {
                    NSLog(@"Yes, anonymousUser identified in objectAtIndex:i for i = %d", i);
                    //if object has the key word im looking for
                    [dictCleanAvatars removeObjectForKey:[keys objectAtIndex:i]]; //remove the key
                    NSLog(@"That's dictCleanAvatars after loop %d: %@", i, dictCleanAvatars);
                }
            }
        }

但这不起作用。

会重视更多经验丰富的 iOS 开发人员的反馈。

Answer 1

如果您尝试构建一个包含 data 中所有内容的数组键的数组，但省略了 profile_picture 的字典包含字符串“AnonymousUser”，您可以使用 NSPredicate :

NSArray *dataArray = responseDictionary[@"data"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"not (profile_picture contains 'AnonymousUser')"];
NSArray *filteredArray = [dataArray filteredArrayUsingPredicate:predicate];

或者您可以使用 predicateWithBlock :

NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(NSDictionary *evaluatedObject, NSDictionary *bindings) {
    return [evaluatedObject[@"profile_picture"] rangeOfString:@"AnonymousUser"].location == NSNotFound;
}];

顺便说一句，如果您已经有一个可变数组，您还可以使用 filterUsingPredicate 从中删除条目，使用上述谓词:

NSMutableArray *mutableDataArray = [responseDictionary[@"data"] mutableCopy];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"not (profile_picture contains 'AnonymousUser')"];
[mutableDataArray filterUsingPredicate:predicate];

另一方面，如果您不想从字典数组中删除整个字典，而是想简单地删除 profile_picture 的出现。对于存在“AnonymousUser”的情况，您要确保不仅数组是可变的，而且其组成字典也是可变的。

最简单的方法是指定 NSJSONReadingMutableContainers解析 JSON 时的选项。然后你可以遍历 NSMutableDictionary条目，删除 profile_picture带有 profile_picture 的条目其中有“AnonymousUser”:

NSMutableDictionary *responseDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:&error];
NSMutableArray *mutableDataArray = responseDictionary[@"data"];

for (NSMutableDictionary *dictionary in mutableDataArray) {
    NSString *profilePicture = dictionary[@"profile_picture"];
    if ([profilePicture rangeOfString:@"AnonymousUser"].location != NSNotFound) {
        [dictionary removeObjectForKey:@"profile_picture"];
    }
}

但是，如果您不能指定 NSJSONReadingMutableContainers当您解析 JSON 并使用不可变集合时，您需要创建一个可变副本。不幸的是，一个简单的 mutableCopy数组的值不会使成员字典本身可变，但您可以使用 Core Foundation 调用 CFPropertyListCreateDeepCopy使用可变条目创建一个可变数组，然后您可以对其进行修改:

NSMutableArray *mutableDataArray = CFBridgingRelease(CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFArrayRef)responseDictionary[@"data"], kCFPropertyListMutableContainers));

那么就可以使用上面的 for循环，遍历这个数组的字典条目，删除有问题的 profile_picture条目。