如何覆盖目标C中的addObserver()方法? 我试过这样做?但是我收到一个编译器错误,说“解析问题表达式'
”- (void)addObserver:(NSObject *)observer
forKeyPath:(NSString *)keyPath
options:(NSKeyValueObservingOptions)options
context:(void *)context
{
[super addObserver:observer forKeyPath:keyPath options:options context:context];
}