保存DeviceToken以便以后在Apple推送通知服务中使用 [英] Saving the DeviceToken for Later Use in Apple Push Notification Services

问题描述

在我的iPhone应用程序中，我从Apple获取设备令牌，我在Delegate文件中分配了一个公共属性，如下所示：

In my iPhone app I am getting the device token from Apple which I am assigning a public property inside the Delegate file as shown below:

- (void)application:(UIApplication*)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData*)deviceToken
{
   self.dToken = [[NSString alloc] initWithData:deviceToken encoding:NSUTF8StringEncoding]; 
}

dToken属性声明如下：

The dToken property is declared as shown below:

NSString *dToken;

@property (nonatomic,retain) NSString *dToken;

但是当我尝试从另一个文件中检索设备令牌时，我得到空值。

But when I try to retrieve the device token from another file I get the null value.

+(NSString *) getDeviceToken
{
  NSString *deviceToken = [(MyAppDelegate *)[[UIApplication sharedApplication] delegate] dToken];

    NSLog(@" getDeviceToken = %@",deviceToken);  // This prints NULL

    return deviceToken; 

}

我做错了什么？

推荐答案

我建议您以这种方式将令牌转换为字符串：

I suggest you to convert token to string in this way:

self.dToken = [[[deviceToken description]
                    stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]] 
                    stringByReplacingOccurrencesOfString:@" " 
                    withString:@""];

更新：
正如很多人提到的，最好使用下一种方法来转换 NSData * 到 NSString * ：

@implementation NSData (Conversion)
- (NSString *)hexadecimalString
{
  const unsigned char *dataBuffer = (const unsigned char *)[self bytes];

  if (!dataBuffer) {
    return [NSString string];
  }

  NSUInteger          dataLength  = [self length];
  NSMutableString     *hexString  = [NSMutableString stringWithCapacity:(dataLength * 2)];

  for (int i = 0; i < dataLength; ++i) {
    [hexString appendFormat:@"%02lx", (unsigned long)dataBuffer[i]];
  }

  return hexString;
}
@end

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