android - 有没有办法在Android(Xamarin)的DatePickerFragment中设置日期

Question

我正在制作一个对话框。在初始状态下，DatePickerFragment 显示当前日期。我将该日期设置为我的 TextView。它工作正常。

下面是代码:

DatePickerFragment 类

public class DatePickerFragment : DialogFragment,
                                  DatePickerDialog.IOnDateSetListener
    {
        public static readonly string TAG = "X:" + typeof(DatePickerFragment).Name.ToUpper();

        // Initialize this value to prevent NullReferenceExceptions.
        Action<DateTime> _dateSelectedHandler = delegate { };

        public static DatePickerFragment NewInstance(Action<DateTime> onDateSelected)
        {
            DatePickerFragment frag = new DatePickerFragment();
            frag._dateSelectedHandler = onDateSelected;

            return frag;
        }

        public override Dialog OnCreateDialog(Bundle savedInstanceState)
        {
            DateTime currently = DateTime.Now;
            DatePickerDialog dialog = new DatePickerDialog(Activity,
                                                           this,
                                                           currently.Year,
                                                           currently.Month - 1,
                                                           currently.Day);
            return dialog;
        }

        public void OnDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth)
        {
            DateTime selectedDate = new DateTime(year, monthOfYear + 1, dayOfMonth);

            _dateSelectedHandler(selectedDate);

        }
    }

在 Activity 上，在我的对话框中使用这种方式。

txt_selectDate = dialog.FindViewById<TextView>(Resource.Id.txt_selectDate);
                        DateTime cuurently = DateTime.Now;
                        txt_selectDate.Text = cuurently.ToString("dd/MM/yyyy",CultureInfo.InvariantCulture);
                        dialog.Show();

                        var select_date = dialog.FindViewById<ImageView>(Resource.Id.select_date);
                        select_date.Click += SelectDate_Click;

然后像这样创建点击方法

void SelectDate_Click(object sender, EventArgs e)
            {
                DatePickerFragment frag = DatePickerFragment.NewInstance(delegate (DateTime time)
                    {
                        var pickupDate = time.ToString("yyyy-MM-dd'T'HH:mm:ss'Z'", CultureInfo.InvariantCulture);
                        txt_selectDate.Text = time.ToString("dd/MM/yyyy", CultureInfo.InvariantCulture);

                    });

                frag.Show(context.FragmentManager, DatePickerFragment.TAG);
            }

问题:

现在，当我再次单击以选择新日期时，DatePickerFragment 显示当前日期而不是之前选择的日期。那么有什么方法可以将上一个日期设置为 DatePickerFragment？

感谢任何帮助。

更新:

添加参数后它会给出这个响应。

Answer 1

我没有使用 DatePickerFragment，而是使用 DatePickerDialog 并通过以下方式解决了我的问题。

这样显示DatePicker

ddtime = new DatePickerDialog(context, OnDateSet, DateTime.Today.Year, DateTime.Today.Month - 1,
                                                     DateTime.Today.Day
                                                             );

                            ddtime.DatePicker.DateTime = selected_Date;
                            ddtime.SetTitle("");
                            ddtime.Show();

它的方法 OnDataSet 就像这样

async void OnDateSet(object sender, DatePickerDialog.DateSetEventArgs e)
            {
                default_date = e.Date.Year + "/" + e.Date.Month + "/" + e.Date.Day;
                txt_selectDate.Text = e.Date.Day + "/" + e.Date.Month + "/" + e.Date.Year;
                selected_Date = e.Date;
            }

最后我的selected_Date 像下面这样在 datePicker 中设置

ddtime.DatePicker.DateTime = selected_Date;