如何在SWIFT 3.0中编写单例类东西

Question

如何在swift 3.0中编写单例类设置。目前我在目标c中使用此代码。  如何在swift 3.0中编写单例类设置。目前我在目标c

中使用此代码

 #pragma mark Singleton
static ModelManager* _instance = nil;

+ (ModelManager *) sharedInstance {
@synchronized([ModelManager class]){
    if (!_instance) {
        _instance = [[self alloc] init];
    }
    return _instance;
}
return nil;
}
+ (id)alloc {
@synchronized([ModelManager class]){

    NSAssert(_instance == nil, @"Attempted to allocate a second instance of a singleton.");
    _instance = [super alloc];
    return _instance;
}
return nil;
}
+ (id)allocWithZone:(NSZone *)zone {
@synchronized([CTEModelManager class]) {
    NSAssert(_instance == nil, @"Attempted to allocate a second instance of a singleton.");
    _instance= [super allocWithZone:zone];
    return _instance; // assignment and return on first allocation
}
return nil; //on subsequent allocation attempts return nil
}
- (id)init {
self = [super init];
if (self != nil) {
}
return self;
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}

Answer 1

Apple终于解决了这个问题，这很简单......

open class Grid {
    static let shared = Grid()

作为一项规则（您可以对此进行无休止的讨论），您可以添加

open class Grid {
    static let shared = Grid()
    fileprivate init() {}

这就是它的全部内容。

要使用单身，你只需＆＃34; Name.shared＆＃34;，所以

 x = Grid.shared.someFunction()

＆＃34;纯糖＆＃34;成语...

考虑一下：Any reason not use use a singleton "variable" in Swift?加法。请注意，它是纯粹的语法糖，或者可能是可卡因，可能适合或不适合您。