属性未显示在我的XCode调试器中

Question

这是我的界面文件：

#import <Foundation/Foundation.h>
#import "TCPServer.h"

@interface OrderReceiverServer : TCPServer <NSStreamDelegate>{

@private
    CFMutableDictionaryRef connections;
}

@property (nonatomic, retain) NSFileManager *fileManager;

- (void)handleNewConnectionFromAddress:(NSData *)addr inputStream:(NSInputStream *)istr outputStream:(NSOutputStream *)ostr;
- (void)setupInputStream:(NSInputStream *)istream outputStream:(NSOutputStream *)ostream;

@end

由于某种原因，属性self.fileManager没有显示在我的XCode调试器中。为什么呢？

我的实施文件以：

开头

#import <Foundation/Foundation.h>
#import "OrderReceiverServer.h"
#import "TCPServer.h"
#import "AppDelegate.h"


@implementation OrderReceiverServer
@synthesize fileManager = _fileManager;