我为我的对象City创建了这个类classCity:NSObject{var_name:String=""varname:String{get{return_name}set(newVal){_name=newVal}}}然后当我创建我的对象时:varcity:City!city.name="London"//crashhereprintln("namecityis\(city.name)");当我使用消息“fatalerror:在展开可选值时意外发现nil”来设置名称时它崩溃了 最佳答案 这实际上不是答案(解决方案请参阅其他答案，
我为我的对象City创建了这个类classCity:NSObject{var_name:String=""varname:String{get{return_name}set(newVal){_name=newVal}}}然后当我创建我的对象时:varcity:City!city.name="London"//crashhereprintln("namecityis\(city.name)");当我使用消息“fatalerror:在展开可选值时意外发现nil”来设置名称时它崩溃了 最佳答案 这实际上不是答案(解决方案请参阅其他答案，
我正在用Swift重写一个Objective-C类，以感受一下这门语言。在Objective-C中，我的类包含以下方法:-(id)initWithCoder:(NSCoder*)aDecoder{return[selfinitWithActionName:[aDecoderdecodeObjectOfClass:[NSStringclass]forKey:@"actionName"]payload:[aDecoderdecodeObjectOfClass:[NSDictionaryclass]forKey:@"payload"]timestamp:[aDecoderdecodeObje
我正在用Swift重写一个Objective-C类，以感受一下这门语言。在Objective-C中，我的类包含以下方法:-(id)initWithCoder:(NSCoder*)aDecoder{return[selfinitWithActionName:[aDecoderdecodeObjectOfClass:[NSStringclass]forKey:@"actionName"]payload:[aDecoderdecodeObjectOfClass:[NSDictionaryclass]forKey:@"payload"]timestamp:[aDecoderdecodeObje
我有一个泛型类，我希望它能够与默认类型一起使用。现在我可以用任何类型初始化它，但我必须明确。//InitializewithatypeMyManager()//InitializewithNSObject(whatIwanttobemydefaulttype)MyManager()//Thisdoesn'twork,butIwantthiskindoffunctionalityclassMyManager{}//SoIcancreatemymanagerlikesoanditinsertsthedefaulttypeasNSObjectMyManager()//OrMyManager(
我有一个泛型类，我希望它能够与默认类型一起使用。现在我可以用任何类型初始化它，但我必须明确。//InitializewithatypeMyManager()//InitializewithNSObject(whatIwanttobemydefaulttype)MyManager()//Thisdoesn'twork,butIwantthiskindoffunctionalityclassMyManager{}//SoIcancreatemymanagerlikesoanditinsertsthedefaulttypeasNSObjectMyManager()//OrMyManager(
如果我使用下面的代码，它会显示错误“类型‘HttpConnection’不符合协议(protocol)‘NSObjectProtocol’”classHttpConnection:NSURLConnectionDataDelegate{varurlConnection:NSURLConnection?weakvardelegate:HttpConnecting?init(delegate:HttpConnecting){self.delegate=delegate;}funcstartAsynRequestWithUrlString(url:NSString,withMethod:NS
如果我使用下面的代码，它会显示错误“类型‘HttpConnection’不符合协议(protocol)‘NSObjectProtocol’”classHttpConnection:NSURLConnectionDataDelegate{varurlConnection:NSURLConnection?weakvardelegate:HttpConnecting?init(delegate:HttpConnecting){self.delegate=delegate;}funcstartAsynRequestWithUrlString(url:NSString,withMethod:NS
Swift中的Hashable协议(protocol)要求您实现一个名为hashValue的属性:protocolHashable:Equatable{///Returnsthehashvalue.Thehashvalueisnotguaranteedtobestable///acrossdifferentinvocationsofthesameprogram.Donotpersistthehash///valueacrossprogramruns.//////Thevalueof`hashValue`propertymustbeconsistentwiththeequality///
Swift中的Hashable协议(protocol)要求您实现一个名为hashValue的属性:protocolHashable:Equatable{///Returnsthehashvalue.Thehashvalueisnotguaranteedtobestable///acrossdifferentinvocationsofthesameprogram.Donotpersistthehash///valueacrossprogramruns.//////Thevalueof`hashValue`propertymustbeconsistentwiththeequality///
