自定义 UIControl 始终发送 nil UIEvent 对象

发布于 2024-11-26 23:01:53 字数 853 浏览 2 评论 0原文

我有一个派生自 UIControl 的类，在其中监视 TouchBegan/Moved/Ended/Cancelled 事件。在这些事件中，我在超级响应者和下一个响应者上调用相同的事件，如下所示：

[self.nextResponder touchesEnded:touches withEvent:event];
[self sendActionsForControlEvents:UIControlEventTouchUpInside];
[super touchesEnded:touches withEvent:event];

我有一个拥有表视图的父控件。表视图中的每个单元格都包含我的自定义控件之一。为了响应单击，我在创建控件并将其添加到表视图单元格时为其分配一个选择器，如下所示：

[myControl addTarget:self action:@selector(myControlTap:withEvent:)forControlEvents:UIControlEventTouchUpInside]; 
[cell.contentView addSubview:myControl];

父控件的选择器如下所示：

- (void)myControlTap:(id)sender withEvent:(UIEvent *)event{
     //UIEvent is always null!
}

有人能告诉我为什么 UIEvent 始终为零吗？如果我使用 UIButton 的实例而不是自定义 UIControl，则 UIEvent 不为零。此外，如果我不在控件中调用 sendActionsForControlEvents ，那么父控件将永远不会收到任何事件通知。

原文

I have a class that derives from UIControl in which I monitor the touchesBegan/Moved/Ended/Cancelled events. Within those events I call the same events on both super and next responder like so:

[self.nextResponder touchesEnded:touches withEvent:event];
[self sendActionsForControlEvents:UIControlEventTouchUpInside];
[super touchesEnded:touches withEvent:event];

I have a parent control that owns a table view. The cells in the table view each contain one of my custom controls. In order to respond to a click I assign a selector to the control when I am creating it and adding it to the table view cell like so:

[myControl addTarget:self action:@selector(myControlTap:withEvent:)forControlEvents:UIControlEventTouchUpInside]; 
[cell.contentView addSubview:myControl];

The parent control's selector looks like this:

- (void)myControlTap:(id)sender withEvent:(UIEvent *)event{
     //UIEvent is always null!
}

Can someone tell me why UIEvent is always nil? If I use an instance of UIButton instead of my custom UIControl then UIEvent is not nil. Furthermore, if I don't call sendActionsForControlEvents in my control then the parent control will never receive any event notifications.

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