有没有办法以编程方式根据计算更改UIStepper的值？

Question

假设我有3 UIStepper s 当我更改值1时，其他步进器的值会根据公式更改。

步进器一个值是10.
步进器二值为5.
步进器三值为3.

如果我更改步进器10 +/- 1，它可能会更改步进器2中的值+/- 1。

这可能吗？

Answer 1

绝对可能。

您可以想象这种情况：

UIStepper *stepperOne = [[UIStepper alloc] initWithFrame:frame];
[stepperOne addTarget:self action:@selector(stepperOneChanged:) forControlEvents:UIControlEventValueChanged];

- (void)stepperOneChanged:(UIStepper*)stepperOne{
    //This method would be called on the target of your first stepper on UIControlEventsValueChanged

    //Decrease the value by 1
    stepperTwo.value --;

    //OR
    //Increase the value by 1
    stepperTwo.value ++;
}

Answer 2

雨燕4.2

 override func viewDidLoad() {
    super.viewDidLoad()

    let stepper = UIStepper(frame: CGRect(x: 100, y: 200, width: 0, height: 0))
    stepper.wraps = true
    stepper.autorepeat = true
    stepper.maximumValue = 20
    stepper.addTarget(self, action: #selector(stepperValueChanged(_:)), for: .valueChanged)
    view.addSubview(stepper)
 }


@objc func stepperValueChanged(_ stepper: UIStepper) {
    print("Chnaged Value: \(stepper.value)")
    stepper.value += 2
    print("Chnaged Value: \(stepper.value)")

}