Iphone 如何在NSNotification中发送对象？

我想将对象发送到NSNotification中的选择器。我的意思是，我有3个按钮，在单击每个按钮时，我正在注册通知，当该事件发生时，我正在调用一个选择器，在该选择器中，我想找出用户单击了哪个按钮，因为我对所有3个按钮都有相同的操作

-(void)allThreeButtonAction:(sender)id
{
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(performSomeOperationWhenEventOccur) name:@"EventCompletedNotification" object:nil];
}

//发生了一些事件，因此我正在发送通知

[[NSNotificationCenter defaultCenter] postNotificationName:@"EventCompletedNotification" object:nil];

//通知方法

-(void)performSomeOperationWhenEventOccur
{
    //Here I want to know which button is pressed.
}

我希望我说的很清楚。

您可能想看看postNotificationName:object:userInfo:from

您只需发送一个UserInfo，其中包含标识按钮所需的任何内容，即指向您在选择器中检索的按钮的指针

您的选择器签名应收到通知：

- (void)performSomeOperationWhenEventOccur:(NSNotification*) notification:(NSNotification*) notification
{
    // Use [notification userInfo] to determine which button was pressed...
}

注册选择器名称时，不要忘记修改它：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(performSomeOperationWhenEventOccur:) name:@"EventCompletedNotification" object:nil];

---

下面的代码片段将帮助您

按钮1

按钮2

将方法更改为以下内容

---

添加通知观察者时无法传递对象，因此必须将按下的按钮存储在某个位置：

-(void)allThreeButtonAction:(id)sender
{
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(performSomeOperationWhenEventOccur) name:@"EventCompletedNotification" object:nil];
   self.buttonPressed = sender;
}

然后，您可以在通知处理程序中读取它：

-(void)performSomeOperationWhenEventOccur
{
    if ( self.buttonPressed = self.button1 )
        ...
}

---

但我将如何在postNotificationName:object:userInfo中发送按钮？我知道只有在注册通知时，在按钮操作中，即当我调用[[NSNotificationCenter defaultCenter]addObserver:self selector:@selectorperformSomeOperationWhenEventOccur:name:@EventCompletedNotification object:nil]；。谢谢你的回复，但我想要的不仅仅是按钮实例信息，还有点击哪个按钮。如果你想传递按钮对象，那么为什么要传递对象：nil。而不是nil pass button对象there@Downvoter如果你足够友善，请保持指出错误和建议正确解决方案的习惯。

- (void) performSomeOperationWhenEventOccur:(NSNotification *) notification
{
    if ([[notification name] isEqualToString:@"button1"])
    {
        NSButton *button1=[notification button1];
        NSLog (@"Successfully received the test notification! from button1");
    }
     else
    {
        NSButton *button2=[notification button2]; 
        NSLog (@"Successfully received the test notification! from button2");
    } 
}

-(void)allThreeButtonAction:(id)sender
{
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(performSomeOperationWhenEventOccur) name:@"EventCompletedNotification" object:nil];
   self.buttonPressed = sender;
}

-(void)performSomeOperationWhenEventOccur
{
    if ( self.buttonPressed = self.button1 )
        ...
}