将参数传递给 addTarget:action:forControlEvents [英] Passing parameters to addTarget:action:forControlEvents

问题描述

我正在使用 addTarget:action:forControlEvents，如下所示:

I am using addTarget:action:forControlEvents like this:

[newsButton addTarget:self
action:@selector(switchToNewsDetails)
forControlEvents:UIControlEventTouchUpInside];

我想将参数传递给我的选择器switchToNewsDetails".我唯一能做的就是通过以下方式传递(id)发件人:

and I would like to pass parameters to my selector "switchToNewsDetails". The only thing I succeed in doing is to pass the (id)sender by writing:

action:@selector(switchToNewsDetails:)

但我试图传递像整数值这样的变量.这样写是行不通的:

But I am trying to pass variables like integer values. Writing it this way doesn't work :

int i = 0;
[newsButton addTarget:self
action:@selector(switchToNewsDetails:i)
forControlEvents:UIControlEventTouchUpInside];

这样写也行不通:

int i = 0;
[newsButton addTarget:self
action:@selector(switchToNewsDetails:i:)
forControlEvents:UIControlEventTouchUpInside];

任何帮助将不胜感激:)

Any help would be appreciated :)

推荐答案

action:@selector(switchToNewsDetails:)

您不要在此处将参数传递给 switchToNewsDetails: 方法.您只需创建一个选择器，使按钮能够在发生某些操作时调用它(在您的情况下进行修改).控件可以使用 3 种类型的选择器来响应动作，它们都有预定义的参数含义:

You do not pass parameters to switchToNewsDetails: method here. You just create a selector to make button able to call it when certain action occurs (touch up in your case). Controls can use 3 types of selectors to respond to actions, all of them have predefined meaning of their parameters:

1. 无参数

action:@selector(switchToNewsDetails)

带1个参数指示发送消息的控件

with 1 parameter indicating the control that sends the message

action:@selector(switchToNewsDetails:)

用2个参数表示发送消息的控件和触发消息的事件:

With 2 parameters indicating the control that sends the message and the event that triggered the message:

action:@selector(switchToNewsDetails:event:)

目前尚不清楚您到底要做什么，但考虑到您想为每个按钮分配一个特定的详细信息索引，您可以执行以下操作:

It is not clear what exactly you try to do, but considering you want to assign a specific details index to each button you can do the following:

1. 为每个按钮设置一个等于所需索引的标签属性

2. 在 switchToNewsDetails: 方法中，您可以获得该索引并打开相应的详细信息:

1. set a tag property to each button equal to required index

2. in switchToNewsDetails: method you can obtain that index and open appropriate deatails:

- (void)switchToNewsDetails:(UIButton*)sender{
    [self openDetails:sender.tag];
    // Or place opening logic right here
}

这篇关于将参数传递给 addTarget:action:forControlEvents的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！