将 NSData 转换为 HEX 字符串

NSData 可以表示为十六进制字符串，类似于它在 description 方法中输出的字符串。

迅速

extension NSData {

    func hexString() -> String {
        return UnsafeBufferPointer<UInt8>(start: UnsafePointer<UInt8>(bytes), count: length)
            .reduce("") { $0 + String(format: "%02x", $1) }
    }

}

Objective-C

@implementation NSData (HexRepresentation)

- (NSString *)hexString {
    const unsigned char *bytes = (const unsigned char *)self.bytes;
    NSMutableString *hex = [NSMutableString new];
    for (NSInteger i = 0; i < self.length; i++) {
        [hex appendFormat:@"%02x", bytes[i]];
    }
    return [hex copy];
}

@end