如何使 UIBarButtonItem 文本在 UIPickerView 中可见？

Question

有没有人遇到过 UIToolbar 中的 UIBarButtonItem 文本（在 UIDatePicker 中调用）在单击此 UIBarButtonItem 之前不可见的问题？什么可能导致这个问题？

Here you can not see the buttons

But when you click on the screen where it is supposed to be you can see that it appears

我尝试了一切，但问题仍然与每个 UIPickerView 相关（包括 UIDatePicker）

这是我的实现：

@objc func createDatePicker() {
        datePicker.datePickerMode = .date

        //ToolBar
        let toolbar = UIToolbar();
        toolbar.sizeToFit()
        let doneButton = UIBarButtonItem(title: "Done", style: .plain, target: self, action: #selector(doneDatePicker));
        let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: nil, action: nil)
        let cancelButton = UIBarButtonItem(title: "Cancel", style: .plain, target: self, action: #selector(cancelDatePicker));
        // I've tried to change color of the label, but it didn't help
        //toolbar.tintColor = UIColor.black
        toolbar.setItems([cancelButton,spaceButton,doneButton], animated: false)


        dateTextfield.inputAccessoryView = toolbar
        dateTextfield.inputView = datePicker
    }

使用此代码，这些按钮是不可见的，但是当您单击这些按钮应该位于的位置时，会出现单击按钮的文本。 但是有没有办法让它一直可见？这种行为的原因可能是什么？

我是ios的新人。所以我会非常感谢你的帮助！提前致谢。

Answer 1

试试这个代码。在这里，我在文本字段中添加 DatePicker 开始编辑。

func openDatePickerForTextField(_ sender: UITextField) {
    //move view if
    moveViewYPositionForDatePicker()
    let datePickerView = UIDatePicker()
    datePickerView.datePickerMode = .date
    sender.inputView = datePickerView
    datePickerView.addTarget(self, action: #selector(handleDatePicker(sender:)), for: .valueChanged)
    addKeyboardToolBar(onTextfield: sender, onPicker: datePickerView)
}

//MARK:- Add done button on Picker View
func addKeyboardToolBar(onTextfield textField : UITextField, onPicker pickerView : UIDatePicker) {
    let keyboardToolBar = UIToolbar(frame: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(pickerView.frame.size.width), height: CGFloat(25)))
    keyboardToolBar.sizeToFit()
    keyboardToolBar.barStyle = .black
    textField.inputAccessoryView = keyboardToolBar
    let nextButton = UIBarButtonItem(title: "Done", style: .plain, target: self, action: #selector(doneButtonPressed))
    keyboardToolBar.items = [UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil), nextButton]
}