ios – 错误处理Swift语言中的Objective-C框架

我正在使用Objective-C框架创建一个iOS
Swift应用程序.

框架头文件(SMPort.h):

// ... do all the import //

@interface PortException : NSException
{
}

@end

@interface PortInfo : NSObject

- (id)initWithPortName:(NSString *)portName_ macAddress:(NSString *)macAddress_ modelName:(NSString *)modelName_;

@property(retain, readonly) NSString *portName;
@property(retain, readonly) NSString *macAddress;
@property(retain, readonly) NSString *modelName;
@property(readonly, getter=isConnected) BOOL connected;

@end

@interface SMPort : NSObject {
    void * m_port;
    WBluetoothPort* wBluetoothPort;
    BluetoothPort* bluetoothPort;
    NSString * m_portName;
    NSString * m_portSettings;
    int m_ioTimeoutMillis;

    BOOL checkedBlockSupport;
}

@property(assign, readwrite, nonatomic) u_int32_t endCheckedBlockTimeoutMillis;

// Initializer and staff methods...

/*!
*  This function retreives the device's detailed status.
*
*  @param starPrinterStatus Pointer to a StarPrinterStatus_n structure where the devices detailed status is written
*                           (either StarPrinterStatus_0, StarPrinterStatus_1, or StarPrinterStatus_2).
*  @param level             Integer designating the level of status structure (either 0, 1, or 2).
*
*  @note Throws PortException on failure.
*/
- (void)getParsedStatus:(void *)starPrinterStatus :(u_int32_t)level;

// The other methods...

我阅读了框架文档,我发现了这个Objective-C代码(完美地运行):

@try
{
    [starPort getParsedStatus:&status :2];
}
@catch (PortException *exception){
    // Print error
}

所以我尝试在Swift 2.1中做这样的事情:

do{
    try starPort.getParsedStatus(status , 2)
}
catch is PortException{
    print("error")
}

但是当错误发生时,编译器会停止应用程序,说我没有捕到该错误:

2015-11-18 18:59:51.297 $$$$$[$$$$$:$$$$$] * Terminating app due to uncaught exception ‘PortException’, reason: ‘Native GetParsedStatusEx failed’
*
First throw call stack:
(0x2524a67b 0x36e76e17 0xa3af7 0x6f378 0x6f3d8 0x6fbc0 0x6fd10 0x6ef00 0x87bf8 0x87d80 0x29371559 0x293714e9 0x293594ff 0x29370e45 0x29370abf 0x2936947f 0x2933a561 0x29338bdb 0x2520dbff 0x2520d7ed 0x2520bb5b 0x2515f119 0x2515ef05 0x2e2fcac9 0x293a1f15 0x7f410 0x375e5873)
libc++abi.dylib: terminating with uncaught exception of type PortException

我也尝试过这样的事情:

func doGPS() throws { starPort.getParsedStatus(status ,2) }
func test() {
   do {
      try doGPS()
   } catch is PortException{
      print("Error")
   } catch{
      print("WTF? : \(error)")
   }
}

test()

得到相同的结果……

那么,我怎样才能在Swift 2.1中捕获这个错误?

这里是SMPort.h https://github.com/gabebear/receiptbooth/blob/master/StarIO.framework/Headers/SMPort.h的完整代码

最佳答案 这个问题问得好!这是一个需要解决的合法问题.不幸的是,你现在无法做到这一点.原因如下:

Swift异常处理与Exceptions无关.实际上,你无法捕获NSException,这是在Obj-C方面提出的. Swift捕获NSError,实际上(在Swift中)是一个Enum.简而言之,在Objective-C中有两种处理错误的模式:1.引发NSException 2.返回NSError

正如我解释的那样,您无法处理使用第一种方法引发的错误.因此,您确实必须使用NSError修改Objective-C代码以符合第二种方法.

一些好的链接:

https://www.bignerdranch.com/blog/error-handling-in-swift-2/
https://forums.developer.apple.com/thread/7582

点赞