Question

如何通过再次按相同的段来取消选择UISegmented控件中的给定段？

E.g。按段0，它将被选中并保持高亮显示。再次按段0，它将被取消选中并且不会突出显示。

该控件仅触发UIControlEventValueChanged事件。其他事件似乎不适用于它。

有一个属性'瞬间'，当设置为YES几乎允许上述行为时，除了突出显示只是暂时的。当momentary = YES按两次相同的段时会导致两个UIControlEventValueChanged事件，但是当瞬间= NO时，只有第一次按下给定的段会导致触发UIControlEventValueChanged事件。即后续按下同一段不会触发UIControlEventValueChanged事件。

Answer 1

你可以继承UISegmentedControl：

Swift 3

class ReselectableSegmentedControl: UISegmentedControl {

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        let previousSelectedSegmentIndex = self.selectedSegmentIndex

        super.touchesEnded(touches, withEvent: event)

        if previousSelectedSegmentIndex == self.selectedSegmentIndex {
            if let touch = touches.first {
                let touchLocation = touch.locationInView(self)
                if CGRectContainsPoint(bounds, touchLocation) {
                    self.sendActionsForControlEvents(.ValueChanged)
                }
            }
        }
    }


}

Swift 4

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    let previousSelectedSegmentIndex = self.selectedSegmentIndex

    super.touchesEnded(touches, with: event)

    if previousSelectedSegmentIndex == self.selectedSegmentIndex {
        let touch = touches.first!
        let touchLocation = touch.location(in: self)
        if bounds.contains(touchLocation) {
            self.sendActions(for: .valueChanged)
        }
    }
}

然后

 @IBAction func segmentChanged(sender: UISegmentedControl) {
    if (sender.selectedSegmentIndex == selectedSegmentIndex) {
        sender.selectedSegmentIndex =  UISegmentedControlNoSegment;
        selectedSegmentIndex = UISegmentedControlNoSegment;
    }
    else {
        selectedSegmentIndex = sender.selectedSegmentIndex;
    }
}

Answer 2

并不是您所要的，但我正在寻找类似的功能并决定了这一点。

向UISegmentedControl添加doubleTap手势，以设置selectedSegmentIndex

初始化UISegmentedControl时。

let doubleTap = UITapGestureRecognizer(target: self, action #selector(YourViewController.doubleTapToggle))
doubleTap.numberOfTapsRequired = 2
yourSegmentedControl.addGestureRecognizer(doubleTap)

取消选择细分的功能

@objc func doubleTapToggle () {
    yourSegmentedControl.selectedSegmentIndex = -1
    yourSegmentedControl.sendActions(for: valueChanged)
}

Answer 3

基于@protspace答案，这是一种更简单的方法，而无需在@IBAction中编写任何内容：

class DeselectableSegmentedControl: UISegmentedControl {
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        let previousSelectedSegmentIndex = selectedSegmentIndex

        super.touchesEnded(touches, with: event)

        if previousSelectedSegmentIndex == selectedSegmentIndex {
            let touch = touches.first!
            let touchLocation = touch.location(in: self)
            if bounds.contains(touchLocation) {
                selectedSegmentIndex = UISegmentedControl.noSegment
                sendActions(for: .valueChanged)
            }
        }
    }
}

Answer 4

可以使用@IBOutlet weak var mySegmentedControl: UISegmentedControl!和mySegmentedControl.selectedSegmentIndex = -1使用Swift以编程方式取消选择UISegmentedControl。至于检测段的触摸，我不知道。希望其他人能得到答案。

UISegmentedControl再次按下取消选择段

4 个答案: