在Objective-C中这很好用
无法在Swift中编译它
要么
IOS SDK中的ALAuthorizationStatus定义
enum ALAuthorizationStatus : Int {
case NotDetermined // User has not yet made a choice with regards to this application
case Restricted // This application is not authorized to access photo data.
// The user cannot change this application’s status,possibly due to active restrictions
// such as parental controls being in place.
case Denied // User has explicitly denied this application access to photos data.
case Authorized // User has authorized this application to access photos data.
}
解决方法
比较运算符==返回Bool,而不是布尔值.
以下编译：
以下编译：
func isAuthorized() -> Bool {
let status = ALAssetsLibrary.authorizationStatus()
return status == ALAuthorizationStatus.Authorized
}
(就个人而言,我发现Swift编译器的错误消息有时令人困惑.
在这种情况下,问题不是==的参数,而是错误的返回类型.)
实际上,由于自动类型推断,还应编译以下内容：
func isAuthorized() -> Bool {
let status = ALAssetsLibrary.authorizationStatus()
return status == .Authorized
}
但它失败了编译器错误“无法找到成员’授权’”,除非你
显式指定状态变量的类型：
func isAuthorized() -> Bool {
let status:ALAuthorizationStatus = ALAssetsLibrary.authorizationStatus()
return status == .Authorized
}
这可能是当前Swift编译器中的一个错误(使用Xcode 6 beta 1测试).
更新：第一个版本现在在Xcode 6.1中编译.