Question

如何计算NSDictionary个对象的总大小？我在NSDictionary中有3000个不同键的StudentClass对象。我想以KB为单位计算字典的总大小。我使用malloc_size()但它总是返回24（NSDictionary包含1个对象或3000个对象） sizeof()也始终返回相同的内容。

Answer 1

你也可以这样找到：

目标C

NSDictionary *dict=@{@"a": @"Apple",@"b": @"bApple",@"c": @"cApple",@"d": @"dApple",@"e": @"eApple", @"f": @"bApple",@"g": @"cApple",@"h": @"dApple",@"i": @"eApple"};

NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:dict forKey:@"dictKey"];
[archiver finishEncoding];

NSInteger bytes=[data length];
float kbytes=bytes/1024.0;
NSLog(@"%f Kbytes",kbytes);

Swift 4

let dict: [String: String] = [
    "a": "Apple", "b": "bApple", "c": "cApple", "d": "dApple", "e": "eApple", "f": "bApple", "g": "cApple", "h": "dApple", "i": "eApple"
]

let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(dict, forKey: "dictKey")
archiver.finishEncoding()

let bytes = data.length
let kbytes = Float(bytes) / 1024.0

print(kbytes)

Answer 2

您可以尝试在数组中获取Dictionary的所有键，然后迭代数组以查找大小，它可能会为您提供字典中键的总大小。

NSArray *keysArray = [yourDictionary allValues];
id obj = nil;
int totalSize = 0;

for(obj in keysArray)
{
    totalSize += malloc_size(obj);
}

Answer 3

我认为，计算大NSDictionary大小的最佳方法是将其转换为NSData并获取数据的大小。祝你好运！

Answer 4

如果你的字典包含标准类（例如NSString）而不是客户字典，那么转换为NSData可能很有用：

NSDictionary *yourdictionary = ...;
NSData * data = [NSPropertyListSerialization dataFromPropertyList:yourdictionary
    format:NSPropertyListBinaryFormat_v1_0 errorDescription:NULL];    
NSLog(@"size of yourdictionary: %d", [data length]);

如何计算NSDictionary对象的总大小？

4 个答案: