ios - NSMutableDictionary 删除键路径处的对象？

Question

我有一个分层的 NSMutableDictionary 对象，我希望能够删除层次结构中更深处的字典。是否有一种快速且简单的方法可以做到这一点，例如类似removeObjectAtKeyPath 的方法？好像找不到啊

谢谢!

Answer 1

没有内置任何内容，但您的基本类别方法就可以了:

@implementation NSMutableDictionary (WSSNestedMutableDictionaries)

- (void)WSSRemoveObjectForKeyPath: (NSString *)keyPath
{
    // Separate the key path
    NSArray * keyPathElements = [keyPath componentsSeparatedByString:@"."];
    // Drop the last element and rejoin the path
    NSUInteger numElements = [keyPathElements count];
    NSString * keyPathHead = [[keyPathElements subarrayWithRange:(NSRange){0, numElements - 1}] componentsJoinedByString:@"."];
    // Get the mutable dictionary represented by the path minus that last element
    NSMutableDictionary * tailContainer = [self valueForKeyPath:keyPathHead];
    // Remove the object represented by the last element
    [tailContainer removeObjectForKey:[keyPathElements lastObject]];
}

@end

注意这要求路径的倒数第二个元素——tailContainer是响应removeObjectForKey:的东西，可能是另一个NSMutableDictionary。如果不是，繁荣!