我找不到任何正式的方法来获得一个UUID字符串退出CBUUID.这些UUID可以是2或16字节长.
目标是将CBUUID存储在一个文件中,作为一个字符串,然后用[CBUUID UUIDWithString：]等重新生成.这是我到目前为止.
// returns a simple 4 byte string for 16bit uuids,128 bit uuids are in standard 8-4-4-4-12 format
// the resulting string can be passed into [CBUUID UUIDWithString:]
+(NSString*)CBUUIDToString:(CBUUID*)cbuuid;
{
NSData* data = cbuuid.data;
if ([data length] == 2)
{
const unsigned char *tokenBytes = [data bytes];
return [NSString stringWithFormat:@"%02x%02x",tokenBytes[0],tokenBytes[1]];
}
else if ([data length] == 16)
{
NSUUID* nsuuid = [[NSUUID alloc] initWithUUIDBytes:[data bytes]];
return [nsuuid UUIDString];
}
return [cbuuid description]; // an error?
}
解决方法
我为CBUUID安装了以下类别：
@interface CBUUID (StringExtraction)
- (NSString *)representativeString;
@end
@implementation CBUUID (StringExtraction)
- (NSString *)representativeString;
{
NSData *data = [self data];
NSUInteger bytesToConvert = [data length];
const unsigned char *uuidBytes = [data bytes];
NSMutableString *outputString = [NSMutableString stringWithCapacity:16];
for (NSUInteger currentByteIndex = 0; currentByteIndex < bytesToConvert; currentByteIndex++)
{
switch (currentByteIndex)
{
case 3:
case 5:
case 7:
case 9:[outputString appendFormat:@"%02x-",uuidBytes[currentByteIndex]]; break;
default:[outputString appendFormat:@"%02x",uuidBytes[currentByteIndex]];
}
}
return outputString;
}
@end
对于此输入：
NSLog(@"UUID string: %@",[[CBUUID UUIDWithString:@"0bd51666-e7cb-469b-8e4d-2742f1ba77cc"] representativeString]); NSLog(@"UUID string2: %@",[[CBUUID UUIDWithString:@"1800"] representativeString]);
它产生以下输出：
UUID string: 0bd51666-e7cb-469b-8e4d-2742f1ba77cc UUID string2: 1800
并保留16字节UUID的适当连字符,同时支持简单的2字节UUID.
