如何抑制单例对象释放？

Question

当多个开发人员正在处理项目时，如何确保我的单例对象不会被错误释放？我们可以处理它的程序吗？

Answer 1

根据Apple关于Creating a Singleton Instance的文档：

static MyGizmoClass *sharedGizmoManager = nil;

+ (MyGizmoClass*)sharedManager
{
    if (sharedGizmoManager == nil) {
        sharedGizmoManager = [[super allocWithZone:NULL] init];
    }
    return sharedGizmoManager;
}

+ (id)allocWithZone:(NSZone *)zone
{
    return [[self sharedManager] retain];
}

- (id)copyWithZone:(NSZone *)zone
{
    return self;
}

- (id)retain
{
    return self;
}

- (NSUInteger)retainCount
{
    return NSUIntegerMax;
}

- (oneway void)release
{
    //do nothing
}

- (id)autorelease
{
    return self;
}

您可能还想阅读以下内容中的答案：What should my Objective-C singleton look like?

Answer 2

暂时这样做，它将确保单身人士不会被释放：

// This function is empty, as we don't want to let the user release this object.
- (oneway void)release {

}

//Do nothing, other than return the shared instance - as this is expected from autorelease.
- (id)autorelease {
    return self;
}