ios - 我无法在注册表单中添加性别的 UIPickerview

Question

我正在创建注册表单，我必须使用选择器 View 将性别包含在文本字段中。但是，我得到的是问号而不是男性和女性。

这是我的代码:

@IBOutlet weak var genderfield: UITextField!

let pickerView = UIPickerView()
let gender1 = ["Male", "Female"]

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

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return gender1.count
}

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return gender1[row]
}

func pickerView(_ pickerView:UIPickerView,didSelectRow row: Int,forComponent component: Int){
    genderfield.text = gender1[row]
    genderfield.resignFirstResponder()
}

在 ViewDidLoad 中:

pickerView.delegate = self
pickerView.dataSource = self
genderfield.inputView = pickerView

我不认为我的代码有什么问题。我已经用谷歌搜索了几个小时。

Answer 1

你得到问号是因为你的 titleForRow 委托(delegate)方法有错误的签名。

改变:

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return gender1[row]
}

到:

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return gender1[row]
}

注意在 ( 之后添加 _。