objective-c - 自定义 NSFastEnumeration 方法？

Question

我有一个将其数据存储在字典中的容器类

我想枚举对象而不是键。

现在我有这样的代码

-(NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(__unsafe_unretained id [])buffer count:(NSUInteger)len
{
    return [self.container countByEnumeratingWithState:state objects:buffer count:len]; // this isn't working as container is dictionary
}

-(myobject *)objectAtIndex:(int)number // this is the method to retrieve a specific object
{
    int i = 0;
    for(id key in self.container) {
        if (number == i) {
            id value = [self.container objectForKey:key];
            return value;
        }
        else i++;
    }
    return nil;
}

Answer 1

为什么不直接使用这样的-allValues属性：

-(NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(__unsafe_unretained id [])buffer count:(NSUInteger)len
{
    return [self.container.allValues countByEnumeratingWithState:state objects:buffer count:len];
}

此外，NSDictionary是一个无序的容器，所以你的-objectAtIndex:方法没有意义。