Ios 如何在分段控制按钮中永久取消选择分段，直到再次单击为止

我有一个带有4个段的

UISegmentedControl

。选择后，应保持

选择状态

。当再次单击同一段时，它应

取消选择自身

。

---

如何实现这一点？

由于

UISegmentedControl

仅在选择了未选择的段时发送操作，因此您必须将

UISegmentedControl

子类化，以对其触摸处理进行微小更改。我使用这个类：

@implementation MBSegmentedControl

// this sends a value changed event even if we reselect the currently selected segment
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    NSInteger current = self.selectedSegmentIndex;
    [super touchesBegan:touches withEvent:event];
    if (current == self.selectedSegmentIndex) {
        [self sendActionsForControlEvents:UIControlEventValueChanged];
    }
}

@end

现在，您将获得

UIControlEventValueChanged

事件，即使已选择该段。只需将当前索引保存在变量中，并在操作中进行比较即可。如果两个索引匹配，则必须取消选择被触摸的段

// _selectedSegmentIndex is an instance variable of the view controller

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    _selectedSegmentIndex = self.segment.selectedSegmentIndex;
}

- (IBAction)segmentChanged:(UISegmentedControl *)sender {
    if (sender.selectedSegmentIndex == _selectedSegmentIndex) {
        NSLog(@"Segment %d deselected", sender.selectedSegmentIndex);
        sender.selectedSegmentIndex =  UISegmentedControlNoSegment;
        _selectedSegmentIndex = UISegmentedControlNoSegment;
    }
    else {
        NSLog(@"Segment %d selected", sender.selectedSegmentIndex);
        _selectedSegmentIndex = sender.selectedSegmentIndex;
    }
}

---

iOS 7改变了UISegmentedControl处理触摸的方式。选择的分段索引现在在

touchesend:

期间更改

因此，更新后的子类应如下所示：

@implementation MBSegmentedControl

+ (BOOL)isIOS7 {
    static BOOL isIOS7 = NO;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        NSInteger deviceSystemMajorVersion = [[[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."] objectAtIndex:0] integerValue];
        if (deviceSystemMajorVersion >= 7) {
            isIOS7 = YES;
        }
        else {
            isIOS7 = NO;
        }
    });
    return isIOS7;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    NSInteger previousSelectedSegmentIndex = self.selectedSegmentIndex;
    [super touchesBegan:touches withEvent:event];
    if (![[self class] isIOS7]) {
        // before iOS7 the segment is selected in touchesBegan
        if (previousSelectedSegmentIndex == self.selectedSegmentIndex) {
            // if the selectedSegmentIndex before the selection process is equal to the selectedSegmentIndex
            // after the selection process the superclass won't send a UIControlEventValueChanged event.
            // So we have to do this ourselves.
            [self sendActionsForControlEvents:UIControlEventValueChanged];
        }
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    NSInteger previousSelectedSegmentIndex = self.selectedSegmentIndex;
    [super touchesEnded:touches withEvent:event];
    if ([[self class] isIOS7]) {
        // on iOS7 the segment is selected in touchesEnded
        if (previousSelectedSegmentIndex == self.selectedSegmentIndex) {
            [self sendActionsForControlEvents:UIControlEventValueChanged];
        }
    }
}

@end

---

Swift 2.2版本，修复了Grzegorz注意到的问题

class ReselectableSegmentedControl: UISegmentedControl {
    @IBInspectable var allowReselection: Bool = true

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        let previousSelectedSegmentIndex = self.selectedSegmentIndex
        super.touchesEnded(touches, withEvent: event)
        if allowReselection && previousSelectedSegmentIndex == self.selectedSegmentIndex {
            if let touch = touches.first {
                let touchLocation = touch.locationInView(self)
                if CGRectContainsPoint(bounds, touchLocation) {
                    self.sendActionsForControlEvents(.ValueChanged)
                }
            }
        }
    }
}

类可重新选择SegmentedControl:UISegmentedControl{
@IBInspectable var allowReselection:Bool=true
覆盖func touchesEnded（触摸：设置，withEvent事件：UIEvent？）{
让previousSelectedSegmentIndex=self.selectedSegmentIndex
super.touchesend（touchs，withEvent:event）
如果AllowSelection&&previousSelectedSegmentIndex==self.selectedSegmentIndex{
如果让触摸=先触摸{
让touchLocation=touch.locationInView（自）
如果CGRectContainsPoint（边界、触摸位置）{
self.sendActionsForControlEvents（.ValueChanged）
}
}
}
}
}

---

Swift 3.0将此修复更改为如下所示：

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

        super.touchesEnded(touches, with: event)

        if previousIndex == selectedSegmentIndex {
            let touchLocation = touches.first!.location(in: self)

            if bounds.contains(touchLocation) {
                sendActions(for: .valueChanged)
            }
        }
    }
}

类MyDecelectableSegmentedControl:UISegmentedControl{
覆盖函数touchesend（touchs:Set，带有事件：UIEvent？）{
让previousIndex=selectedSegmentIndex
super.touchesend（触摸，带有：事件）
如果previousIndex==selectedSegmentIndex{
让touchLocation=touchs.first！.location（in:self）
if bounds.contains（触摸位置）{
sendActions（针对：.valueChanged）
}
}
}
}

以下是一个问题的解决方案，当您尝试通过点击UISegmentControl来取消选择，然后再点击外部，它仍然会取消选择

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint locationPoint = [[touches anyObject] locationInView:self];
CGPoint viewPoint = [self convertPoint:locationPoint fromView:self];
if ([self pointInside:viewPoint withEvent:event]) {
    int oldValue = self.selectedSegmentIndex;
    [super touchesEnded:touches withEvent:event];
    if (oldValue == self.selectedSegmentIndex)
    {
        [super setSelectedSegmentIndex:UISegmentedControlNoSegment];
        [self sendActionsForControlEvents:UIControlEventValueChanged];
    }
}
}

---

非常有帮助！非常感谢。我希望对我的项目的事件有更多的控制，所以我修改了@Matthias的答案，以发送一个定制的“值未更改”事件。我举了一个例子

---

我还加入了@Grzegorz的修复程序，因此如果用户将手指拖到分段控件之外，它会正常工作。

这里有一个独立于IOS版本的解决方案。它选择的是行为本身

@interface CustomSegmentedControl : UISegmentedControl
@end




@implementation CustomSegmentedControl{


BOOL _touchBegan;
BOOL _reactOnTouchBegan;
}



- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    _touchBegan = YES;

    NSInteger previousSelectedSegmentIndex = self.selectedSegmentIndex;
    [super touchesBegan:touches withEvent:event];
    if (_reactOnTouchBegan) {
        // before iOS7 the segment is selected in touchesBegan
        if (previousSelectedSegmentIndex == self.selectedSegmentIndex) {
            [self sendActionsForControlEvents:UIControlEventValueChanged];
        }
    }
}


-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    _touchBegan = NO;

    NSInteger previousSelectedSegmentIndex = self.selectedSegmentIndex;
    [super touchesEnded:touches withEvent:event];
    if (!_reactOnTouchBegan) {
        CGPoint locationPoint = [[touches anyObject] locationInView:self];
        CGPoint viewPoint = [self convertPoint:locationPoint fromView:self];
        if ([self pointInside:viewPoint withEvent:event]) {
            // on iOS7 the segment is selected in touchesEnded
            if (previousSelectedSegmentIndex == self.selectedSegmentIndex) {
                [self sendActionsForControlEvents:UIControlEventValueChanged];
            }
        }
    }
}


- (void)sendActionsForControlEvents:(UIControlEvents)controlEvents {
    if(controlEvents == UIControlEventValueChanged){
        _reactOnTouchBegan = _touchBegan;
    }
    [super sendActionsForControlEvents:controlEvents];
}


@end

---

您可以通过以下方式完成此操作（谢谢您和）：

---

我制作了一个开源（麻省理工学院许可）类（支持iOS 7+），其中包含了此功能（以及更多）。

参考@Matthias Bauch发布的答案。我不得不按照Xcode 7.3中的Swift 2.2做一些小改动：

class ReselectableSegmentedControl: UISegmentedControl {
    @IBInspectable var allowReselection: Bool = true
    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        let previousSelectedSegmentIndex = self.selectedSegmentIndex
        super.touchesEnded(touches, withEvent: event)
        if allowReselection && previousSelectedSegmentIndex == self.selectedSegmentIndex {
            if let touch = touches.first {
                let touchLocation = touch.locationInView(self)
                if CGRectContainsPoint(bounds, touchLocation) {
                    self.sendActionsForControlEvents(.ValueChanged)
                }
            }
        }
    }
}

类可重新选择SegmentedControl:UISegmentedControl{
@IBInspectable var allowReselection:Bool=true
覆盖func touchesEnded（触摸：设置，withEvent事件：UIEvent？）{
让previousSelectedSegmentIndex=self.selectedSegmentIndex
super.touchesend（touchs，withEvent:event）
如果AllowSelection&&previousSelectedSegmentIndex==self.selectedSegmentIndex{
如果让触摸=先触摸{
让touchLocation=touch.locationInView（自）
如果CGRectContainsPoint（边界、触摸位置）{
self.sendActionsForControlEvents（.ValueChanged）
}
}
}
}
}

swift3.1版本由@Kushal Ashok发布

class ReselectableSegmentedControl: UISegmentedControl {
    @IBInspectable var allowReselection: Bool = true

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        let previousSelectedSegmentIndex = self.selectedSegmentIndex
        super.touchesEnded(touches, with: event)
        if allowReselection && previousSelectedSegmentIndex == self.selectedSegmentIndex {
            if let touch = touches.first {
                let touchLocation = touch.location(in: self)
                if bounds.contains(touchLocation) {
                    self.sendActions(for: .valueChanged)
                }
            }
        }
    }
}

类可重新选择SegmentedControl:UISegmentedControl{
@IBInspectable var allowReselection:Bool=true
覆盖函数touchesend（touchs:Set，带有事件：UIEvent？）{
让previousSelectedSegmentIndex=self.selectedSegmentIndex
super.touchesend（触摸，带有：事件）
如果AllowSelection&&previousSelectedSegmentIndex==self.selectedSegmentIndex{
如果让触摸=先触摸{
让touchLocation=touch.location（in:self）
if bounds.contains（触摸位置）{
self.sendActions（针对：.valueChanged）
}
}
}
}
}

关于@Stunner，这是我为实现目标所做的贡献。我更改了一些内容并添加了属性\u previousSelectedSegmentIndex；在@Stunner代码中，变量previousSelectedSegmentIndex无效：

@implementation STASegmentedControl
{
    NSInteger _previousSelectedSegmentIndex;
}

- (void)setSelectedSegmentIndex:(NSInteger)selectedSegmentIndex
{
    [super setSelectedSegmentIndex: selectedSegmentIndex];

    _previousSelectedSegmentIndex = self.selectedSegmentIndex;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];

    CGPoint locationPoint = [[touches anyObject] locationInView:self];
    CGPoint viewPoint = [self convertPoint:locationPoint fromView:self];
    if (self.toggleableSegments) { // toggle selected segment on/off
        if ([self pointInside:viewPoint withEvent:event] && _previousSelectedSegmentIndex == self.selectedSegmentIndex) {
            self.selectedSegmentIndex = UISegmentedControlNoSegment;
            [self sendActionsForControlEvents:UIControlEventValueChanged];
        }
    }
    _previousSelectedSegmentIndex = self.selectedSegmentIndex;
}

---

当iOS7发布时，这个答案第二次帮助了我。我应该能够再次向上投票。您还可以通过添加

self.selectedSegmentIndex=UISegmentedControlNoSegment，将取消选择的代码封装在此子类中在<代码>[自发送操作ForControlEvents:UIControlEventValueChanged]之前该解决方案的问题是，当您开始触摸组件并将其拖动到组件外部以取消触摸时，它仍然会取消选择项目，这是一个非常好的解决方案！谢谢
[self pointInside:withEvent]
使用分段控件的可见维度。如果我使用它并触摸内部，然后在释放之前向外拖动一点，它会使片段呈现浅蓝色，就像我的手指仍然向下，并且不会发送事件。有没有办法知道控件的命中测试区域，以查看该点是否在该区域内？
@implementation STASegmentedControl
{
    NSInteger _previousSelectedSegmentIndex;
}

- (void)setSelectedSegmentIndex:(NSInteger)selectedSegmentIndex
{
    [super setSelectedSegmentIndex: selectedSegmentIndex];

    _previousSelectedSegmentIndex = self.selectedSegmentIndex;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];

    CGPoint locationPoint = [[touches anyObject] locationInView:self];
    CGPoint viewPoint = [self convertPoint:locationPoint fromView:self];
    if (self.toggleableSegments) { // toggle selected segment on/off
        if ([self pointInside:viewPoint withEvent:event] && _previousSelectedSegmentIndex == self.selectedSegmentIndex) {
            self.selectedSegmentIndex = UISegmentedControlNoSegment;
            [self sendActionsForControlEvents:UIControlEventValueChanged];
        }
    }
    _previousSelectedSegmentIndex = self.selectedSegmentIndex;
}