0
我正在使用xamarin格式。我想在日曆控件中綁定Web服務。請參閱下面的日曆控件鏈接（XamForms.Controls.Calendar）。如何從不是異步方法調用異步方法？
https://github.com/rebeccaXam/XamForms.Controls.Calendar
第一功能是創建7 * 6 = 42個標籤和按鈕然後「callWebService」方法來調用服務函數，它是異步方法來獲得從服務響應。
protected void FillCalendarWindows()
{
try
{
for (int r = 0; r < 6; r++)
{
for (int c = 0; c < 7; c++)
{
if (r == 0)
{
labels.Add(new Label
{
HorizontalOptions = LayoutOptions.Center,
VerticalOptions = LayoutOptions.Center,
TextColor = Color.Black,
FontSize = 18,
FontAttributes = FontAttributes.Bold
});
DayLabels.Children.Add(labels.Last(), c, r);
}
buttons.Add(new CalendarButton
{
BorderRadius = 0,
BorderWidth = BorderWidth,
BorderColor = BorderColor,
FontSize = DatesFontSize,
BackgroundColor = DatesBackgroundColor,
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand
});
buttons.Last().Clicked += DateClickedEvent;
MainCalendar.Children.Add(buttons.Last(), c, r);
}
}
flag = 1;
//Device.BeginInvokeOnMainThread(() => CallWebService(StartDate.Month, StartDate.Year));
CallWebService(StartDate.Month, StartDate.Year);
//CallServiceInNewTask(StartDate.Month, StartDate.Year);
//Device.BeginInvokeOnMainThread(() => ChangeCalendar(CalandarChanges.All));
}
catch (Exception e)
{
}
}
二功能是「callWebService」功能，我收集列表集合對象響應然後調用它是用來綁定標籤和按鈕上的文字，並填寫相應的顏色「ChangeClaendar」功能。
public async void CallWebService(int Month, int Year)
{
try
{
var response = await GetResponseFromWebService.GetResponse<ServiceClasses.RootObject_AttendanceTable>(ServiceURL.GetAttendanceTableList + "Month=" + Month + "&Year=" + Year + "&EmpCd=" + _empCode);
if (response.Flag == true)
{
if (ListObjAttendanceTblList == null)
{
ListObjAttendanceTblList = new List<LstAttendanceDtl>();
}
for (int i = 0; i < response.lstAttendanceDtl.Count; i++)
{
var objAttendanceTableList = new LstAttendanceDtl();
objAttendanceTableList.AttendanceDt = response.lstAttendanceDtl[i].AttendanceDt;
objAttendanceTableList.EarlyDeparture = response.lstAttendanceDtl[i].EarlyDeparture;
objAttendanceTableList.InTime = response.lstAttendanceDtl[i].EarlyDeparture;
objAttendanceTableList.LateArrival = response.lstAttendanceDtl[i].EarlyDeparture;
objAttendanceTableList.OutTime = response.lstAttendanceDtl[i].OutTime;
objAttendanceTableList.OverTime = response.lstAttendanceDtl[i].OverTime;
objAttendanceTableList.Reason = response.lstAttendanceDtl[i].Reason;
objAttendanceTableList.Remark = response.lstAttendanceDtl[i].Remark;
objAttendanceTableList.Shift = response.lstAttendanceDtl[i].Shift;
objAttendanceTableList.WorkingHrs = response.lstAttendanceDtl[i].WorkingHrs;
ListObjAttendanceTblList.Add(objAttendanceTableList);
}
}
else
{
}
if (flag == 1)
{
ChangeCalendar(CalandarChanges.All);
}
else
{
ChangeCalendar(CalandarChanges.StartDate);
}
}
catch (WebException e)
{
}
}
第三個功能是 「ChangeCalendar」
protected void ChangeCalendar(CalandarChanges changes)
{
try
{
if (changes.HasFlag(CalandarChanges.StartDate))
{
Device.BeginInvokeOnMainThread(() => CenterLabel.Text = StartDate.ToString(TitleLabelFormat));
}
var start = CalendarStartDate;
var beginOfMonth = false;
var endOfMonth = false;
for (int i = 0; i < buttons.Count; i++)
{
endOfMonth |= beginOfMonth && start.Day == 1;
beginOfMonth |= start.Day == 1;
LstAttendanceDtl objAttendanceDtl = ListObjAttendanceTblList.Find(s => s.AttendanceDt.Equals(start.Date.ToString("dd/MM/yyyy")));
string remarks = string.Empty;
if (i < 7 && WeekdaysShow && changes.HasFlag(CalandarChanges.StartDay))
{
Device.BeginInvokeOnMainThread(() => labels[i].Text = start.ToString(WeekdaysFormat));
//labels[i].Text = start.ToString(WeekdaysFormat);
//DateTime d = Convert.ToDateTime(objAttendanceDtl.AttendanceDt).Date;
}
if (changes.HasFlag(CalandarChanges.All))
{
Device.BeginInvokeOnMainThread(()=>buttons[i].Text = string.Format("{0}", start.Day));
//buttons[i].Text = string.Format("{0}", start.Day);
}
else
{
Device.BeginInvokeOnMainThread(() => buttons[i].TextWithoutMeasure = string.Format("{0}", start.Day));
}
buttons[i].Date = start;
var isInsideMonth = beginOfMonth && !endOfMonth;
if (objAttendanceDtl != null)
{
remarks = objAttendanceDtl.Remark;
if ((remarks.ToLower()).Trim() == stringFullDay.ToLower().Trim())
{
SetButtonPresent(buttons[i], isInsideMonth);
}
else if (remarks.ToLower().Trim() == stringAbsent.ToLower().Trim())
{
SetButtonAbsent(buttons[i], isInsideMonth);
}
else if (remarks.ToLower().Trim() == stringWeekOff.ToLower().Trim())
{
SetButtonWeekendMood(buttons[i], isInsideMonth);
}
else if (remarks.ToLower().Trim() == stringHolidays.ToLower().Trim())
{
SetButtonHolidays(buttons[i], isInsideMonth);
}
else if (remarks.ToLower().Trim() == stringSecondhalfAbsent.ToLower().Trim() ||
remarks.ToLower().Trim() == stringFirsthalfAbsent.ToLower().Trim())
{
SetButtonHalfDayMood(buttons[i], isInsideMonth);
}
else
{
SetButtonDisabled(buttons[i]);
}
}
else
{
SetButtonOutSideMonth(buttons[i]);
}
SpecialDate sd = null;
if (SpecialDates != null)
{
sd = SpecialDates.FirstOrDefault(s => s.Date.Date == start.Date);
}
if (sd != null)
{
SetButtonSpecial(buttons[i], sd);
}
else if (SelectedDate.HasValue && start.Date == SelectedDate.Value.Date)
{
SetButtonSelected(buttons[i], isInsideMonth);
}
start = start.AddDays(1);
}
}
catch (Exception e)
{
}
}
的問題是：
在 「Changecalendar」 功能，當我嘗試直接填寫標籤列表
labels[i].Text = start.ToString(WeekdaysFormat);
它顯示我的錯誤
「UIKit的一致性錯誤：您所調用只能從UI線程調用的方法的UIKit」所以要去除這個錯誤，我寫
Device.BeginInvokeOnMainThread(() => labels[i].Text = start.ToString(WeekdaysFormat));
Device.BeginInvokeOnMainThread(()=>buttons[i].Text = string.Format("{0}", start.Day));
Device.BeginInvokeOnMainThread(() => buttons[i].TextWithoutMeasure = string.Format("{0}", start.Day));
，但它顯示我的錯誤
System.ArgumentOutOfRangeException：索引超出範圍。必須是非負數且小於集合的大小。
2.如果我把兩個功能「CallWebService」和「ChangeCalendar」在「FillCalendarWindow」一個接一個，然後列表對象未綁定和控制出來的功能，直接ChangeCalendar函數調用，並給我空參考對象。
你想等到方法完成任務嗎？ – Atul
第一個函數是CallWebService，第二個函數是ChangeCalendar。完成第一個功能後應該調用第二個功能。但在我的情況下，在CallWebService（）函數控件中並沒有去這行「If（response.flag == true）」（控件退出函數）並直接調用ChangeCalendar（）方法。 –