检测UITableView滚动

问题描述

我已经将UITableView（作为KRTableView）子类化，并实现了四种基于触摸的方法（touchesBegan，touchesEnded，touchesMoved和touchesCancelled），以便我可以检测在UITableView上处理基于触摸的事件的时间。基本上我需要检测是当UITableView向上或向下滚动。然而，子类化UITableView和创建上述方法只会检测当UITableViewCell中发生滚动或手指移动时，而不是整个UITableView。

一旦我的手指移动到下一个单元格，触摸事件不做任何事情。

这是我对子类化UITableView的方法：

  #import KRTableView.h
 
 
 @implementation KRTableView 
 
  - （void）touchesBegan：（NSSet *）touches withEvent：（UIEvent *）event {
 [super touchesBegan：touches withEvent：event]; 
 NSLog（@touches begins ...）; 
} 
 
  - （void）touchesMoved：（NSSet *）touches withEvent：（UIEvent *）event {
 [super touchesMoved：touches withEvent：event]; 
 NSLog（@touchesMoved occured）; 
} 
 
  - （void）touchesCancelled：（NSSet *）touches withEvent：（UIEvent *）event {
 [super touchesCancelled：touches withEvent：event]; 
 NSLog（@touchesCancelled occured）; 
} 
 
  - （void）touchesEnded：（NSSet *）touches withEvent：（UIEvent *）event {
 [super touchesEnded：touches withEvent：event]; 
 NSLog（@在KRTableView上检测到轻击）; 
} 
 
 @end 
  

UITableView是向上还是向下滚动？

解决方案

您不需要截取事件方法。检查文档的 UIScrollViewDelegate 协议，并实现 -scrollViewDidScroll：或 -scrollViewWillBeginDragging： 适合您的情况的方法。

I've subclassed UITableView (as KRTableView) and implemented the four touch-based methods (touchesBegan, touchesEnded, touchesMoved, and touchesCancelled) so that I can detect when a touch-based event is being handled on a UITableView. Essentially what I need to detect is when the UITableView is scrolling up or down.

However, subclassing UITableView and creating the above methods only detects when scrolling or finger movement is occuring within a UITableViewCell, not on the entire UITableView.

As soon as my finger is moved onto the next cell, the touch events don't do anything.

This is how I'm subclassing UITableView:

#import "KRTableView.h"


@implementation KRTableView

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesBegan:touches withEvent:event];
    NSLog(@"touches began...");
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesMoved:touches withEvent:event];
  NSLog(@"touchesMoved occured");
}

- (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent *)event {
    [super touchesCancelled:touches withEvent:event];
  NSLog(@"touchesCancelled occured");
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
  [super touchesEnded:touches withEvent:event];
  NSLog(@"A tap was detected on KRTableView");
}

@end

How can I detect when the UITableView is scrolling up or down?

解决方案

You don't need to intercept the event methods. Check the docs for the UIScrollViewDelegate protocol, and implement the -scrollViewDidScroll: or -scrollViewWillBeginDragging: methods as appropriate to your situation.

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