试图使用下面的代码块,但不知道如何让选项位在else子句中工作,我不断得到’nspropertyListMutabilityOptions’不能转换为’nspropertyListReadOptions’.但Read选项没有我需要的MutableContainersWithLeaves.
//if the file does not already exist if(appStatsData != nil) { appStats.setobject(NSNumber.numberWithInt(0),forKey:"runcount") appStats.setobject("No Courses Viewed",forKey:"LastCourseViewed") }else { appStats = nspropertyListSerialization.propertyListWithData(appStatsData,options: nspropertyListMutabilityOptions.MutableContainersAndLeaves,format: nil,error: &error) }
options参数的类型为nspropertyListReadOptions,它是一种类型别名
对于Int.
对于Int.
nspropertyListMutabilityOptions是一个RawOptionSetType,其中Uint作为底层
原始类型.
因此,您必须将选项转换为Int with
appStats = nspropertyListSerialization.propertyListWithData(appStatsData,options:Int(nspropertyListMutabilityOptions.MutableContainersAndLeaves.rawValue),error: &error)