Question

我有一个名为Account的类，有6个属性，其中一个属性是c结构。我无法弄清楚如何使用NSCoding来遵守结构。我将如何编码和解码c struct属性。结构是app_config_t类型。

结构

typedef struct app_config_t
{
    pj_pool_t               *pool;

    pjsua_config            cfg;
    pjsua_logging_config    log_cfg;
    pjsua_media_config      media_cfg;

    pjsua_transport_config  udp_cfg;
    pjsua_transport_config  rtp_cfg;


    pj_bool_t               ringback_on;
    pj_bool_t               ring_on;

    int                     ringback_slot;
    int                     ringback_cnt;
    pjmedia_port            *ringback_port;

    int                     ring_cnt;
    SystemSoundID           ring_id;
    CFRunLoopTimerRef       ring_timer;
} app_config_t;

一个名为'Account'的Objective-C类，其属性为App_config

#pragma mark - NSCoding
- (void) encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:self.Username forKey:@"username"];
    [aCoder encodeObject:self.Password forKey:@"password"];
    [aCoder encodeObject:self.Server forKey:@"server"];

    [aCoder encodeInt:self.Account_id forKey:@"Account_id"];
    [aCoder encodeInt:self.Call_id forKey:@"Call_id"];

    //trying to save this object, is this even correct
    NSMutableData *data = [NSMutableData dataWithBytes:&_App_config length:sizeof(app_config_t)];
    NSKeyedArchiver *App_config_Archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    [aCoder encodeObject:App_config_Archiver forKey:@"App_config"];
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super init])
    {
        self.Username = [aDecoder decodeObjectForKey:@"username"];
        self.Password = [aDecoder decodeObjectForKey:@"password"];
        self.Server = [aDecoder decodeObjectForKey:@"server"];

        self.Account_id = [aDecoder decodeIntForKey:@"Account_id"];
        self.Call_id = [aDecoder decodeIntForKey:@"Call_id"];

        self.App_config = ?????????

    }

    return self;
}

Answer 1

您当前的编码代码有错误。 Archiver使用您为NSKeyedArchiver提供的可变数据来存储编码数据。因此复制app_config_t结构是没用的。

您需要使用NSKeyedArchiver对结构的每个字段进行编码。它具有原始类型的编码器。同样在app_config_t结构中，我看到的字段不是基本类型，而是复杂类型。所以你也需要为这些字段定制编码。

- (void) encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:self.Username forKey:@"username"];
    [aCoder encodeObject:self.Password forKey:@"password"];
    [aCoder encodeObject:self.Server forKey:@"server"];

    [aCoder encodeInt:self.Account_id forKey:@"Account_id"];
    [aCoder encodeInt:self.Call_id forKey:@"Call_id"];

    // this data will have encoded structure
    NSMutableData *data = [NSMutableData data];
    NSKeyedArchiver *App_config_Archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];

    // for all fields from structure you need to use such encoders
    [App_config_Archiver encodeBool:_App_config.ringback_on forKey:@"ringback_on"];

    // encode data itself
    [aCoder encodeObject:data forKey:@"App_config"];
}

Answer 2

您应该能够将结构视为内存缓冲区并使用NSCoder的encodeBytes function来执行此操作：

- (void)encodeBytes:(const void * _Nullable)byteaddr length:(NSUInteger)length

NSCoding一个c结构对象，它是类的属性

2 个答案: