一直以來使用的解析方式（iOS13之前）都是如下：

Objective-C:

NSString *token = [[deviceToken description] stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]];
token = [token stringByReplacingOccurrencesOfString:@" " withString:@""];

Swift:

let dataStr = NSData(data: deviceToken)
let token = dataStr.description
  .replacingOccurrences(of: "<", with: "")
  .replacingOccurrences(of: ">", with: "")
  .replacingOccurrences(of: " ", with: "")

//當然下面這種方式性能更好：
let charactersToRemove: Set<Character> = ["<", ">", " "]
let tokenNew = dataStr.description.removeAll(where: charactersToRemove.contains)

或者類似的解析方式数尿，都是替換< >和空字符串這種方法.

在stackoverflow中有人說過這樣的解析方式并不好，但是一直沒有問題嫩实，所以大家也就習慣了這樣的解析方式了，但是iOS13中這樣的解析方式就有問題了
大家可以更新解析方式為下面這樣的方式（兼容各個版本）：
Objective-C: （這個是友盟提供的方法）

- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken
{
    if (![deviceToken isKindOfClass:[NSData class]]) return;
    const unsigned *tokenBytes = [deviceToken bytes];
    NSString *hexToken = [NSString stringWithFormat:@"%08x%08x%08x%08x%08x%08x%08x%08x",
                          ntohl(tokenBytes[0]), ntohl(tokenBytes[1]), ntohl(tokenBytes[2]),
                          ntohl(tokenBytes[3]), ntohl(tokenBytes[4]), ntohl(tokenBytes[5]),
                          ntohl(tokenBytes[6]), ntohl(tokenBytes[7])];
    NSLog(@"deviceToken:%@",hexToken);
}

Objective-C: (另一種方法)

if (![deviceToken isKindOfClass:[NSData class]]) return;
NSMutableString *valueString = [NSMutableString string];
const unsigned *tokenBytes = [deviceToken bytes];
NSInteger count = deviceToken.length;
for (int i = 0; i < count; i++) {
    [valueString appendFormat:@"%02x", tokenBytes[i]&0x000000FF];
}

//這個也可改成for in 循環(huán)獲取

Swift:和上面方法基本一致朦乏，使用高級函數(shù)一行搞定

let token = deviceToken.map{String(format: "%02.2hhx", $0)}.joined()

或

let token = deviceToken.map{String(format: "%02x", $0)}.joined()

或者

let token = deviceToken.reduce("", {$0 + String(format: "%02x", $1)}) 

賞我一個贊吧~~~