目标c中的单身人士

Question

我在objective-c书上看到了一个单例.但是,我不知道在objective-c和其他lang之间是否存在'singleton'定义的含义不同.这个[[SingletonClass alloc] init]是否仍可用于创建新对象？如果是,如何保证内存中只有一个对象？

#import "SingletonClass.h"

@implementation SingletonClass

static SingletonClass *sharedInstance = nil;

// Get the shared instance and create it if necessary.
+ (SingletonClass*)sharedInstance {
    if (sharedInstance == nil) {
        sharedInstance = [[super allocWithZone:NULL] init];
    }

    return sharedInstance;
}

// We can still have a regular init method, that will get called the first time the             Singleton is used.
- (id)init
{
    self = [super init];

    if (self) {
        // Work your initialising magic here as you normally would
    }

    return self;
}

Answer 1

Colin Wheeler 在Cocoa有一篇关于Singletons的帖子.

我同意科林关于单身人士不受欢迎的观点.