swift - 在 Swift 中使用 Objective C/C

Question

我在 swift 中使用 objective-c /c 库时遇到问题。

    for i in results {
        print(i.interface.index)
    }

当我尝试访问对象的属性“interface”时，我从 Swift 收到此错误:

“AnyObject”类型的值没有成员接口(interface)。

但是“i”是一个 MidiBusInterface 对象，我可以在这里查看:

Screenshot

@interface MidiBusInterface : NSObject
{
    @public
    MIDIBUS_INTERFACE* interface;
}

typedef struct midibus_interface
{
   uint8_t index;

   eMidiBusInterfaceType type;

   eMidiBusInterfaceMode mode;

   uint8_t transport;

   char* ident;

   bool_t enabled;

   bool_t network_connections;

   uint64_t event_count;  

   uint64_t transport_delay_average_mt;

   uint64_t transport_delay_average_deviation_mt;

   bool_t clock_running;                // clock is running
   uint64_t start_tick_count;           // total number of ticks since start
   uint64_t cont_tick_count;            // ticks since continue (or start)
   float current_bpm;                   // current bpm measured
   float  min_bpm, max_bpm, avg_bpm;    // min/max/avg bpm this clock run
   float bpm_average_deviation_percent; // bpm standard deviation %

   bool_t present;                           // interface present
   uint64_t tick_anchor_mt;                  // timestamp of start/cont event
   uint64_t last_tick_timestamp_received_mt; // timestamp of last tick
   bool_t is_owner;                          // set to true if app owns        interface
} MIDIBUS_INTERFACE;

有什么线索吗？

非常感谢!

Answer 1

结果是 Objective C 集合吗？您需要将结果转换为 MidiBusInterface 类型，例如:

for i in results as? [MidiBusInterface] {
        print(i.interface.index)
    }