UISegmentedControl get previous selected index

Question

I have a UISegmentedControl with a segmentedValueChanged method on it. I need to find out what was the selected index before this method is called . How to do this?

Store it in a property, or subclass UISegmentedControl and override the method when a segment is selected and update a stored value there — Tim, Oct 30 '13 at 10:33

Alex · Accepted Answer · 2013-10-30T12:53:25.070

Use this function:

@property (nonatomic, assign) NSInteger oldSegmentedIndex;
@property (nonatomic, assign) NSInteger actualSegmentedIndex;
.......

- (void)viewDidLoad
{
    .......
    self.oldSegmentedIndex = -1;
    self.actualSegmentedIndex = self.segmentedControl.selectedSegmentIndex;
    .......
}
.......
- (IBAction)didSegmentedValueChanged:(id)sender
{
    //Do whatever you want
    self.oldSegmentedIndex = self.actualSegmentedIndex;
    self.actualSegmentedIndex = self.segmentedControl.selectedSegmentIndex;
}

score 3 · Answer 2 · answered Oct 30 '13 at 10:27

3

The best way is to keep a variable that holds the last selected index. Then you just check it's value when you need

answered Oct 30 '13 at 10:27

Zalykr

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score 2 · Answer 3 · answered Aug 01 '17 at 22:02

There is also a nice solution with key-value observing. Here the code for Swift 3:

class SegmentedControl: UISegmentedControl {

    private(set) var previousSelectedSegmentIndex: Int?

    override func willChangeValue(forKey key: String) {
        if key == #keyPath(selectedSegmentIndex) {
            previousSelectedSegmentIndex = selectedSegmentIndex
        }
        super.willChangeValue(forKey: key)
    }

}

UISegmentedControl get previous selected index

3 Answers3