目标 C：如何将 NSString 转换为 UInt8 数组

Question

I had one tag in my code as below

static const UInt8 publicKeyIdentifier[] = "com.example.zone\0";
Now in place of "com.example.zone" i need to use following String "nameWithZoneId" 

NSString id = @"123456";
NSString *nameWithZoneId = [@"com.example.zone" stringByAppendingString:id];

so i can use tag as dynamic way eg. "com.example.zone123456\\0"; Thanks in advance.

Answer 1

You could create a Tag class to keep count of the tag value for each specified identifier ( "com.example.zone" in your example).

Tag.h:

@interface Tag : NSObject
+ (NSString *)nextTagForIdentifier:(NSString *)identifier
@end

Tag.m:

static NSMutableDictionary *_identifiers = nil;

@implementation Tag

+ (NSString *)nextTagForIdentifier:(NSString *)identifier
{
    if (_identifiers == nil)
        _identifiers = [NSMutableDictionary new];
    NSUInteger value = [_identifiers[identifier] unsignedInteger] + 1;
    _identifiers[identifier] = @(value);
    return [NSString stringWithFormat:@"%@%lu", identifier, value];
}

@end

And you would use it like this:

NSString *nameWithZoneId = [Tag nextTagForIdentifier:@"com.example.zone"];