ios 如何在 Swift 中使用多个组件更改 UIPickerView 的文本颜色？
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How do I change the text color of UIPickerView with multiple components in Swift?
提问by KML
Below code will change the font colour of the picker view of all 3 components. However, it crash when I try to spin the wheel. I think it has to do with the didSelectRow function. Maybe the two function have to be nested somehow? Any idea?
下面的代码将更改所有 3 个组件的选择器视图的字体颜色。但是，当我尝试旋转轮子时它会崩溃。我认为这与 didSelectRow 函数有关。也许这两个函数必须以某种方式嵌套？任何的想法？
func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
var attributedString: NSAttributedString!
if component == 0 {
attributedString = NSAttributedString(string: a.text!, attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
}
if component == 1 {
attributedString = NSAttributedString(string: b.text!, attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
}
if component == 2 {
attributedString = NSAttributedString(string: c.text!, attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
}
return attributedString
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int){
switch component {
case 0:
aOutput.text = a[row] --> **Code breaks**
case 1:
bOutput.text = b[row]
case 2:
cOutput.text = c[row]
default:
10
}
回答by Imanou Petit
The following pickerView:attributedTitleForRow:forComponent:method implementation should help you:
以下pickerView:attributedTitleForRow:forComponent:方法实现应该可以帮助您：
func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
let attributedString = NSAttributedString(string: "some string", attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
return attributedString
}
Update
更新
If you want to use attributedStringin multiple ifor switchstatements, the following UIViewControllersubClass example will help you:
如果您想attributedString在多个iforswitch语句中使用，以下UIViewControllersubClass 示例将帮助您：
import UIKit
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
@IBOutlet weak var picker: UIPickerView!
let arrayOne = ["One", "Two", "Three", "Four", "Five", "Six"]
let arrayTwo = ["Un", "Deux", "Trois", "Quatre", "Cinq", "Six"]
let arrayThree = [1, 2, 3, 4, 5, 6]
override func viewDidLoad() {
super.viewDidLoad()
picker.delegate = self
picker.dataSource = self
}
func numberOfComponentsInPickerView(_: UIPickerView) -> Int {
return 3
}
func pickerView(_: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
switch component {
case 0:
return arrayOne.count
case 1:
return arrayTwo.count
case 2:
return arrayThree.count
default:
return NSNotFound
}
}
func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
var attributedString: NSAttributedString!
switch component {
case 0:
attributedString = NSAttributedString(string: arrayOne[row], attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
case 1:
attributedString = NSAttributedString(string: arrayTwo[row], attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
case 2:
attributedString = NSAttributedString(string: toString(arrayThree[row]), attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
default:
attributedString = nil
}
return attributedString
}
func pickerView(_: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
switch component {
case 0:
println(arrayOne[row])
case 1:
println(arrayTwo[row])
case 2:
println(arrayThree[row])
default:
break
}
}
}
回答by Thinesh
Swift 4.0
斯威夫特 4.0
func pickerView(_ pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
return NSAttributedString(string: pickerData[row], attributes: [NSAttributedStringKey.foregroundColor : UIColor.white])
}
回答by Marcos Reboucas
Swift 3
斯威夫特 3
func pickerView(_ pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
let attributedString = NSAttributedString(string: "YOUR STRING", attributes: [NSForegroundColorAttributeName : UIColor.white])
return attributedString
}
