android - Kotlin DatePicker弹出窗口在 fragment 内不起作用:WindowManager $ BadTokenException:无法添加窗口- token null无效；

Question

android.view.WindowManager $ BadTokenException:无法添加窗口- token null无效；您的 Activity 正在进行吗？

我试图从this弹出DatePicker，并且在将其放入片段之前，它工作正常。DatePickerDialog(...).show()发生错误
而且我认为由于片段的上下文，它无法正常工作。

这是代码(在片段中)

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Inflate the layout for this fragment
    val view: View = inflater!!.inflate(R.layout.fragment_fill1, container, false)

    textview_date = view.text_view_date
    button_date = view.button_date
    textview_date!!.text = "--/--/----"

    // create an OnDateSetListener
    val dateSetListener = object : DatePickerDialog.OnDateSetListener {
        override fun onDateSet(
            view: DatePicker, year: Int, monthOfYear: Int,
            dayOfMonth: Int
        ) {
            cal.set(Calendar.YEAR, year)
            cal.set(Calendar.MONTH, monthOfYear)
            cal.set(Calendar.DAY_OF_MONTH, dayOfMonth)
            updateDateInView()
        }
    }

    button_date!!.setOnClickListener(object : View.OnClickListener {
        override fun onClick(view: View) {
            DatePickerDialog(
                getActivity()!!.getApplicationContext(), //Context to fill
                dateSetListener,
                // set DatePickerDialog to point to today's date when it loads up
                cal.get(Calendar.YEAR),
                cal.get(Calendar.MONTH),
                cal.get(Calendar.DAY_OF_MONTH)
            ).show() //Error on this line
        }

    })

    // Return the fragment view/layout
    return view
}

//Date Picker
private fun updateDateInView() {
    val myFormat = "dd/MM/yyyy" // mention the format you need
    val sdf = SimpleDateFormat(myFormat, Locale.US)
    textview_date!!.text = sdf.format(cal.getTime())
}

谢谢!!

Answer 1

对话框需要 Activity 上下文。

更换

getActivity()!!.getApplicationContext()

与

requireActivity()