1.普通创建法
static let shareSingleOne = Single()
2.静态创建法(苹果推荐使用,安全高效)
let single = Single()
class Single: NSObject {
class var sharedInstance2 : Single {
return single
}
}
3.struct创建法
static var shareInstance3:Single{
struct MyStatic{
static var instance :Single = Single()
}
return MyStatic.instance;
}