点击已选择的段时检测事件

Question

嗨我想在触摸已经选定的片段时获得活动.

我已实施以下解决方案

import UIKit

class MARSSegmentController: UISegmentedControl {

    /*
    // Only override drawRect: if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func drawRect(rect: CGRect) {
    // Drawing code
    }
    */

    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
        let oldValue:NSInteger = self.selectedSegmentIndex
        super.touchesBegan(touches, withEvent: event)
        if oldValue == self.selectedSegmentIndex{
            sendActionsForControlEvents(UIControlEvents.ValueChanged)
        }
    }    
} 

这工作正常,但如果我点击非选定的段,ValueChanged事件将被执行两次.

实现点按手势无效.表示当我点击未选择的片段时,它会在使用点按手势时显示旧的所选片段.

如有任何解决方案请建议.

Answer 1

我意识到这是一个较旧的问题,但我遇到了同样的问题,我需要检测是否选择了现有的段以及所选的段更改.

上面的解决方案很接近,但这对我有用.在touchesBegan上捕获现有的选定段索引,然后在touchesEnded中,将旧值与当前选定的段索引进行比较.如果它们相同,我手动触发.ValueChanged事件.注意:这是Swift 2.0语法.

class SegmentedControlExistingSegmentTapped : UISegmentedControl
{
    // captures existing selected segment on touchesBegan
    var oldValue : Int!

    override func touchesBegan( touches: Set<UITouch>, withEvent event: UIEvent? )
    {
        self.oldValue = self.selectedSegmentIndex
        super.touchesBegan( touches , withEvent: event )
    }

    // This was the key to make it work as expected
    override func touchesEnded( touches: Set<UITouch>, withEvent event: UIEvent? )
    {
        super.touchesEnded( touches , withEvent: event )

        if self.oldValue == self.selectedSegmentIndex
        {
            sendActionsForControlEvents( .ValueChanged )
        }
    }
}

Answer 2

我认为你的问题基于这样一个事实，if oldValue == self.selectedSegmentIndex因为 . 总是会返回 true let oldValue:NSInteger = self.selectedSegmentIndex。因此，您所需要做的就是更改 if 条件，其中if oldValue == selectedValueselectedValue 是您认为选择的分段的值