在UItextField中选择具有相同选择器视图的行后（在选择器视图中）不可选择

Question

我一直在寻找答案，但我找不到任何明确的解决方案。我正在使用具有相同UIpickerViews的三个UItextField创建一个视图控制器。如果已在另一个UItextField中选择了特定行，则如何使特定行无法选择更改颜色或消失？

这是我的代码：

 }
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return Array.count

}
func pickerView(_ pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
    if "Shake" {
    let attributesUnavailable = [NSForegroundColorAttributeName: UIColor.gray]
    let attributedTitle = NSAttributedString(string: "Shake", attributes: attributesUnavailable)
        return attributedTitle
    }

    let attributesAvailable = [NSForegroundColorAttributeName: UIColor.black]
    let attributedTitle = NSAttributedString(string: Array[row], attributes: attributesAvailable)
    return attributedTitle
}

public func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 1
}

func donePicker() {
    actionTextField1.resignFirstResponder()
    actionTextField2.resignFirstResponder()
    actionTextField3.resignFirstResponder()

}

@IBAction func save3(_ sender: AnyObject) {
    if (behaviorTextField1.text?.isEmpty)! {
        let behavior1Empty = UIAlertController (title: "Error", message: "Please fill-In Behavior Names and set corresponding Actions", preferredStyle: UIAlertControllerStyle.alert)

        self.present(behavior1Empty, animated:true, completion:nil)

         behavior1Empty.addAction(UIAlertAction(title: "Okay", style: UIAlertActionStyle.default, handler: { (action: UIAlertAction!) in


    }))

}
}
    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

        if Array[row] {
            pickerView.selectRow(row + 1, inComponent: 0, animated: true)
        }
    }
    if pickerView.tag == 1 {
        actionTextField1.text = Array[row]

    }
    else if pickerView.tag == 2 {
        actionTextField2.text = Array[row]
    }
    else {
        actionTextField3.text = Array[row]

} 帮助将受到高度赞赏！

Answer 1

它不像UITableView那么简单，但有一个很好的方法，在Settings.app设置IOS日期时似乎使用了相同的方法。

• 首先将无效的行标题属性颜色设置为灰色，以便用户知道此行不可用： pickerView(_:attributedTitleForRow:forComponent:)

示例：

func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {

if row_cant_be_selected {
    let attributesUnavailable = [NSForegroundColorAttributeName: UIColor.grayColor()]
    let attributedTitle = NSAttributedString(string: YOUR_TITLE_FOR_ROW, attributes: attributesUnavailable)
    return attributedTitle
}

let attributesAvailable = [NSForegroundColorAttributeName: UIColor.blackColor()]
let attributedTitle = NSAttributedString(string: YOUR_TITLE_FOR_ROW, attributes: attributesUnavailable)
return attributedTitle
}

• 然后使用委托方法pickerView(_:didSelectRow:inComponent:)来了解用户何时选择了不可用的行。在这种方法中，只需将selectRow(_:inComponent:animated:)调用为＆＃34;强制＆＃34;另一行选择。

示例：

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

        if ROW_CANT_BE_SELECTED {
            pickerView.selectRow(row + 1, inComponent: 0, animated: true)
        }
}

IE：如果第1行不可用，请在pickerView(_:didSelectRow:inComponent:上拨打pickerView.selectRow(row + 1, inComponent: 0, animated: true)。这将使UIPickerView跳到下一个元素。请注意最后一个元素。

请注意row + 1，如果当前row是最后一个，则应该row - 1。

其他方法是删除数据源中的那些不可用元素。只需重新加载其他选择器视图数据。