iphone - postNotification 正确触发函数，但 userinfo(NSDictionary) 没有任何内容

Question

我使用下面的代码来通知菜单选择索引

    NSDictionary *userInfo=  [NSDictionary dictionaryWithObject:[NSString stringWithFormat:@"123"] 
                                              forKey:@"Index"];
   [[NSNotificationCenter defaultCenter] postNotificationName: @"notifyToMenuSelectionNotification"
                                                    object: userInfo];



-(void)menuSelectionNotification:(NSNotification *)notification
{
  NSLog(@"%@", notification.userInfo);


}

menuSelectionNotification 已正确触发，

但是 NSLog 输出 notification.userInfo 仍然是 {null}

欢迎任何评论1

Answer 1

您以错误的方式传递对象。请尝试这个 -

NSDictionary *userInfo=  [NSDictionary dictionaryWithObject:[NSString stringWithFormat:@"123"] 
                                              forKey:@"Index"];

[[NSNotificationCenter defaultCenter] postNotificationName:@"notifyToMenuSelectionNotification"
                                      object:nil
                                      userInfo:userInfo];