如何更改 UISegmentedControl 索引更改时显示的内容？

Question

我的分段 controller 有一个小问题，并尝试在单击新索引时更改向用户显示的视图。 我设置了代码以显示用户在更改索引时输入的文本框。 一个问题是我想在分段的 controller 下均匀放置文本框，另一个问题是当我单击 controller 中的新索引时，之前的文本框仍在屏幕上，但我需要它只显示与所选特定索引相关的文本框。 代码如下所示，我在其中创建了段 controller 并处理了索引的切换以及文本框的创建。

    let segmentedControl: UISegmentedControl = {
        let sc = UISegmentedControl(items: ["Inventory", "Sale", "Expense"])
        sc.selectedSegmentIndex = 0
        sc.layer.cornerRadius = 9
        sc.layer.borderWidth = 1
        sc.layer.borderColor = UIColor.lightGray.cgColor
        sc.layer.masksToBounds = true

        sc.addTarget(self, action: #selector(handleSegmentChange), for: .valueChanged)
        return sc
    }()

    //function to handle click of segmented control buttons
    @objc fileprivate func handleSegmentChange(sender: UISegmentedControl){
        print(segmentedControl.selectedSegmentIndex)

        switch segmentedControl.selectedSegmentIndex{
        case 0:
            view.addSubview(myProduct)
        case 1:
            view.addSubview(myRetail)
        default:
            view.addSubview(myExpense)
            break
        }

    }

    let myProduct : UITextField = {
        let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 10))
        mp.placeholder = "Enter Product name"
        mp.borderStyle = UITextField.BorderStyle.line
        mp.backgroundColor = .white
        mp.textColor = .cyan

        return mp
        }();

    let myRetail : UITextField = {
        let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 20))
        mp.placeholder = "Enter Retail price"
        mp.borderStyle = UITextField.BorderStyle.line
        mp.backgroundColor = .white
        mp.textColor = .cyan

        return mp
        }();

    let myExpense : UITextField = {
        let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 30))
        mp.placeholder = "Enter Expense name"
        mp.borderStyle = UITextField.BorderStyle.line
        mp.backgroundColor = .white
        mp.textColor = .cyan

        return mp
        }();

我看到的大多数解决方案都已过时，这就是我在这里发布自己的版本的原因。 提前感谢任何人都可以提供的帮助。

Answer 1

您可以为每个UITextField设置tag ，如下所示，

let myProduct : UITextField = {
    let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 10))
    mp.placeholder = "Enter Product name"
    mp.borderStyle = UITextField.BorderStyle.line
    mp.backgroundColor = .white
    mp.textColor = .cyan
    mp.tag = 11
    return mp
}()

let myRetail : UITextField = {
    let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 20))
    mp.placeholder = "Enter Retail price"
    mp.borderStyle = UITextField.BorderStyle.line
    mp.backgroundColor = .white
    mp.textColor = .cyan
    mp.tag = 12
    return mp
}()

let myExpense : UITextField = {
    let mp = UITextField(frame: CGRect(x: 10, y: 320, width: 300, height: 30))
    mp.placeholder = "Enter Expense name"
    mp.borderStyle = UITextField.BorderStyle.line
    mp.backgroundColor = .white
    mp.textColor = .cyan
    mp.tag = 13
    return mp
}()

然后在handleSegmentChange中，在添加新视图之前删除带有该标签的任何视图，如下所示，

//function to handle click of segmented control buttons
@objc fileprivate func handleSegmentChange(sender: UISegmentedControl){
    print(segmentedControl.selectedSegmentIndex)

    [11, 12, 13].forEach { self.view.viewWithTag($0)?.removeFromSuperview() }

    switch segmentedControl.selectedSegmentIndex {
    case 0:
        view.addSubview(myProduct)
    case 1:
        view.addSubview(myRetail)
    default:
        view.addSubview(myExpense)
    }
}

对于 position 问题，您没有为UISegmentControl设置任何帧。 您可以如下设置frame以获得显示的结果，

let segmentedControl: UISegmentedControl = {
    let sc = UISegmentedControl(items: ["Inventory", "Sale", "Expense"])
    sc.selectedSegmentIndex = 0
    sc.layer.cornerRadius = 9
    sc.layer.borderWidth = 1
    sc.layer.borderColor = UIColor.lightGray.cgColor
    sc.layer.masksToBounds = true
    sc.frame = CGRect(origin: CGPoint(x: 10, y: 280), size: CGSize(width: 300, height: 30))

    sc.addTarget(self, action: #selector(handleSegmentChange), for: .valueChanged)
    return sc
}()