本文介绍了PickerView 只显示 '?'的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
这是我的源代码，我所做的是在 storyBoard 上创建选择器视图.通过控制+拖动在此控制器中制作 IBOutlet.
This is my source code and what I have done is make picker view on storyBoard. Make IBOutlet in this controller by contorl+drag.
它可以编译但是，只有'?'出现在选择器视图中.
It can be compiled however, only '?' appears in the picker view.
问题出在哪里?
import UIKit
class SelectViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate{
var songNames = ["test1","test2","test3"]
@IBOutlet weak var songPicker: UIPickerView!
override func viewDidLoad(){
songPicker.delegate = self
songPicker.dataSource = self
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return songNames.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int) -> String? {
return songNames[row]
}
}
推荐答案
您遗漏了 dataSource 方法中的 forComponent 参数.将它添加到您的 titleForRow 函数中，如下所示:
You have missed the forComponent parameter from the dataSource method. Add it in your titleForRow function like this:
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return songNames[row]
}
这应该可以解决您遇到的问题.
This should fix the problem you are having.
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