Culture Aware Month Calendar and DatePicker

Hello,
I have error CS0246, namespace "CustomControls" cannot be found.

Anything I missed ?

Hi, If user selected some date range, then how can the user get the highlight date range?
such as, user choose 2018-01-01 ~ 2018-01-05 firstly, and then choose 2018-02-01 ~ 2018-02-12 secondly. At last, how to get the hightlighted date range?

Without going into details how and why, A Hebrew year has a variable number of months, Standard non-leap years have 12 months, vs leap years are having 13 months. in a Hebrew calendar a leap year occurs every 2 to 3 years.

In a leap year the month called "Ader" (אדר) is being doubled to "Ader-1"(30 days) and "Ader-2"(29 days).

With this being said, the Calendar Control of this projects shows the month names for every year as they would be leap year, so for month of "Nissen" it shows "Ader 2" and so on, until reaching 12 months, and then skipping the moth of "Elul" starting the next year!

changing line 342 and 367 in MonthCalendarFormatProvider.cs to

C#

: this.monthNames[month < 7 ? month - 1 : month ];

solves the issue Thumbs Up | :thumbsup:

hi
when change calture to persian , numbers of day and years show in current format but month name dont change in persian.
how can solve this problem ?

sh-a

How can I make a DatePicker display an empty string?

Apparently, the Windows system itself has issues with the "first week of the year" setting for different cultures.

A specific example that had us stumped was that regional format set to "French (France)" used CalendarWeekRule.FirstDay instead of CalendarWeekRule.FirstFourDayWeek. The bizarre thing is that "French (Belgium)" gives the same wrong result, while "Dutch (Belgium)" correctly uses CalendarWeekRule.FirstFourDayWeek.

In other words, this rule seems to change depending on the language rather than the region.

The best fix for this seems to be to change Helper\DateMethods.cs and build correction code into the GetWeekOfYear(...) function, like this:

C#

public static Int32 GetWeekOfYear(CultureInfo info, Calendar cal, DateTime date)
{
    CultureInfo ci = info ?? CultureInfo.CurrentUICulture;
    Calendar c = cal ?? ci.Calendar;
    CalendarWeekRule cwr;
    String regionName = new RegionInfo(ci.LCID).TwoLetterISORegionName;
    if ("FR".Equals(regionName) || "BE".Equals(regionName))
        cwr = CalendarWeekRule.FirstFourDayWeek;
    // any more such fixes can be handled here with "else if"s
    else
        cwr = ci.DateTimeFormat.CalendarWeekRule;
    return c.GetWeekOfYear(date, cwr, ci.DateTimeFormat.FirstDayOfWeek);
}

modified 1-Dec-15 4:18am.

For me "Dutch (Belgium)" also gives the wrong rule CalendarWeekRule.FirstDay. Cannot change this at Windows level. I wonder where this is defined.

Hi Thomas,
FOA a great project you have here! Thanks so much for sharing.

Secondly, could yo add an option to stop the current year from being marked (orange) in the year picking dropdown, and to make the current date in line with others/not bold?

Found how to do it if it helps someone else.

MonthCalendarRenderer.cs line 330 remove the today check leaving only the right side of the statement:

C#

bool useBoldFont = day.Date == DateTime.Today || bold;

MonthCalendar.cs line 3265 also removing the check and leaving only the desired parts:

C#

item.Font = year == this.CultureCalendar.GetYear(DateTime.Today) ?
   new Font("Tahoma", 8.25F, FontStyle.Bold)
   : new Font("Tahoma", 8.25F, FontStyle.Regular);
item.ForeColor = year == this.CultureCalendar.GetYear(DateTime.Today) ?
   Color.FromArgb(251, 200, 79)
   : Color.Black;

Very good component, I use it since 1 year.
This day, I discover 2 bugs :
1) Textbox shows now.date, but now.date is < mindate, so textbox should show mindate !
2) If you set as mindate 27/04/2015 to datepicker, when it displays calendar, it starts on may, and 27 to 30 april are not visible !

for 1st point I changed this :
DatePickerTexBoxDate.cs, line 193 : this block cutted and pasted after mindate and maxdate controls

C#

if (value == this.currentDate)
{
   return;
}

and On DatePicker.cs, mindate and maxdate properties, added :

this.dateTextBox.Date = this.dateTextBox.Date;// Change to mindate if current date < mindate

For second point, I don't find... Confused | :confused:

please help

Hi Thomas,

You have another bug in your source in the ExtensionMethods class:

C#

public static bool Contains(this SelectionRange range, DateTime date)
{
   date = date.Date;

   if (range.Start == DateTime.MinValue)
   {
      return date == range.End;
   }

   if (range.End == DateTime.MinValue)
   {
      return date == range.Start;
   }

   return date >= range.Start && date <= range.End;
}

For this to function the comparison with range.Start should be with DateTime.MaxValue. In addition comparing with the range when you already know the true comparison seems inappropriate. I would propose that the comparison should be with DateTime.MinValue and DateTime.MaxValue respectively.

That gives you this replacement code:

C#

public static bool Contains(this SelectionRange range, DateTime date)
{
   date = date.Date;

   if (range.Start == DateTime.MaxValue)
   {
      return date == DateTime.MaxValue;
   }

   if (range.End == DateTime.MinValue)
   {
      return date == DateTime.MinValue;
   }

   return date >= range.Start && date <= range.End;
}

Hope that this is helpful. I will keep you posted on anything else I discover.

If you have the time and the inclination I would also like to understand why you chose to implement the SelectionRange property and all the code to adjust its content in various scenarios, rather than simply storing all the ranges in the SelectionRanges property? I cannot yet see any benefit other than perhaps backward compatibility with the WinForms month calendar...

This is Best..
Thank You Sir... Smile | :)

Thank you very much!

Bye,

Thomas.

Hi Thomas,

This is great work, and in many ways very close to what I needed. How MS could not forsee that people live in different parts of the world and might want to set multiple dates is beyond me!!

However, although I have only been working on it a short while there are a number of problems with the source that should ideally be addressed, at least one before the source will compile! Firstly, you have references in the source to BoldedDateType* which all need to be changed to BoldedDateCategory* to allow the project to build.

Secondly, the UpdateMonths method has a problem with MinDate and MaxDate being set to less than a month apart. To resolve this, check for monthList.Count being > zero before breaking:

C#

/// <summary>
///     Updates the shown months.
/// </summary>
public void UpdateMonths()
{
    int x = 0, y = 0, index = 0;
    int calendarWidthDimension = _calendarDimensions.Width;
    int calendarHeightDimension = _calendarDimensions.Height;

    var monthList = new List<MonthCalendarMonth>();

    var dt = new MonthCalendarDate(CultureCalendar, _viewStart);

    if (dt.GetEndDateOfWeek(_formatProvider).Month != dt.Month)
    {
        dt = dt.GetEndDateOfWeek(_formatProvider).FirstOfMonth;
    }

    if (UseRTL)
    {
        x = _monthWidth * (calendarWidthDimension - 1);

        for (int i = 0; i < calendarHeightDimension; i++)
        {
            for (int j = calendarWidthDimension - 1; j >= 0; j--)
            {
                if (monthList.Count > 0 && dt.Date >= _maxDate)
                {
                    break;
                }

                monthList.Add(new MonthCalendarMonth(this, dt.Date)
                {
                    Location = new Point(x, y),
                    Index = index++
                });

                x -= _monthWidth;
                dt = dt.AddMonths(1);
            }

            x = _monthWidth * (calendarWidthDimension - 1);
            y += _monthHeight;
        }
    }
    else
    {
        for (int i = 0; i < calendarHeightDimension; i++)
        {
            for (int j = 0; j < calendarWidthDimension; j++)
            {
                if (monthList.Count > 0 && dt.Date >= _maxDate)
                {
                    break;
                }

                monthList.Add(new MonthCalendarMonth(this, dt.Date)
                {
                    Location = new Point(x, y),
                    Index = index++
                });

                x += _monthWidth;
                dt = dt.AddMonths(1);
            }

            x = 0;
            y += _monthHeight;
        }
    }

    if (monthList.Count > 0)
    {
        _lastVisibleDate = monthList[monthList.Count - 1].LastVisibleDate;
        _months = monthList.ToArray();
    }
}

The next thing that did not work for me was that there was no way to get or set a list of selected dates which it seemed to me was the most likely way that users would want to populate and consume the dates. Certainly for my purposes (a dialog where the user can select a number of dates to be processed in some way) it was the obvious way to do things. Whilst I could have retrieved the ranges and processed them in my code that section of code would have to be repeated every time it was needed so it made sense to be able to get the dates in and out as an IEnumberable<datetime> which would be easy and save lots of repetitive code every time that was what was wanted.

The following is an early start, but all the unit tests I have set up confirm that it is working thus far - until someone finds otherwise Smile | :)

First thing is to define the property:

C#

/// <summary>
/// Gets or sets the selected dates.
/// </summary>
[Description("The selected dates in the month calendar.")]
public IEnumerable<DateTime> SelectedDates
{
    get { return GetSelectedDates(); }

    set { SetSelectedDates(value); }
}

Now we need the two main methods for the getter:

XML

private IEnumerable<DateTime> GetSelectedDates()
{
    // Use a HashSet to store the dates, as it will automatically prevent duplicates
    // and not throw and exception if a duplicate should arise
    var set = new HashSet<DateTime>();

    // Pick up all available SelectionRanges
    var ranges = new List<SelectionRange> { SelectionRange };
    ranges.AddRange(SelectionRanges);

    foreach (var selectionRange in ranges)
    {
        var rangeDates = GetDatesFromRange(selectionRange);
        foreach (var dateTime in rangeDates)
        {
            set.Add(dateTime);
        }
    }

    var dates = set.ToArray();
    Array.Sort(dates);
    return dates;
}

private static IEnumerable<DateTime> GetDatesFromRange(SelectionRange selectionRange)
{
    var set = new HashSet<DateTime>();
    var startDate = selectionRange.Start;
    var endDate = selectionRange.End;
    var currentDate = startDate;

    set.Add(currentDate);
    currentDate = currentDate.AddDays(1);

    while (currentDate <= endDate)
    {
        set.Add(currentDate);
        currentDate = currentDate.AddDays(1);
    }

    return set;
}

Here we use a HashSet to get quick elimination of duplicates i.e. we need the currently selected date as well as any dates in the SelectionRanges, and it is possible for one or more duplicates to arise. We grab the SelectionRange plus all SelectionRanges in a list, then iterate them grabbing out all the dates. Finally, sort them into date order and return the list.

The setter is a different issue, not least because we have to decide how to handle any dates passed in that are outside the range of MinDate to MaxDate? It might be critical that we know should this occur and therefore throwing an exception would be essential, or we might not care, and want to simply ignore any such dates. I could foresee situations where either might be appropriate, so my solution was to add an enum and a property to handle it:

XML

/// <summary>
/// Gets or sets the way that invalid dates are handled
/// </summary>
[DefaultValue(InvalidDateAction.Ignore)]
[Category("Behavior")]
[Description("Determines the way that invalid dates are handled.")]
public InvalidDateAction InvalidDateAction { get; set; }

XML

/// <summary>
/// The InvalidDateAction enum
/// </summary>
public enum InvalidDateAction
{
    Ignore,
    ThrowException
}

Note that the defalt value is Ignore, since I felt that was the most likely requirement. However, you can change the default in the code above or just set it how you want it in the constructor or initialisation code like this:

InvalidDateAction = InvalidDateAction.ThrowException;

You could also set it on the fly once the calendar exists on your form:

monthCalendar1.InvalidDateAction = InvalidDateAction.ThrowException;

OK. Now we are ready to deal with the Setter method:

C#

private void SetSelectedDates(IEnumerable<DateTime> dates)
{
    if (dates == null)
    {
        throw new ArgumentNullException("dates", @"Dates value must not be null");
    }

    try
    {
        BeginUpdate();

        // Clear out the existing ranges
        _selectionRanges.Clear();

        var list = dates as List<DateTime> ?? dates.ToList();
        if (!list.Any())
        {
            return;
        }

        // Ensure that the dates are in ascending date order
        list.Sort((a, b) => a.CompareTo(b));

        // Check for any invalid dates
        //Loop backwards so we can remove invalid dates if necessary
        for (int i = list.Count - 1; i >= 0; i--)
        {
            var currentDate = list[i];
            if (currentDate < _minDate || currentDate > _maxDate)
            {
                // Handle Invalid Date
                switch (InvalidDateAction)
                {
                    case InvalidDateAction.Ignore:
                        list.RemoveAt(i);
                        break;
                    case InvalidDateAction.ThrowException:
                        throw new ArgumentOutOfRangeException("dates", @"Passed set of dates contains values outside the permitted range of dates");
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
        }

        // Select the first date to assign to the range
        var selectedDate = list[0];

        // Split them into ranges
        var ranges = GetRanges(list);

        // Add in the returned ranges
        foreach (var selectionRange in ranges)
        {
            _selectionRanges.Add(selectionRange);
        }

        _selectionStart = selectedDate;
        _selectionEnd = selectedDate;
    }
    finally
    {
        EndUpdate();
    }
}

First thing we do is to check for a null list, and thrown an exception if one is located. Next we call BeginUpdate to stop the calendar redrawing and clear out the selected dates, since that will be required regardless of the number of dates passed in.

The next step is to check for an empty list, and if we find one we get out as we have done all that is necessary - passing an empty list is equivalent to clearing the all the ranges.

Then we sort the dates into date order just in case they were passed in out of order. This is important because we need to convert the dates into one or more ranges in order to assign them to the calendar and that won't work properly with an unordered list.

Now we are at the point where we need to handle the invalid dates. We must either remove the dates from the list (InvalidDateAction.Ignore) or throw an exception (InvalidDateAction.ThrowException). By going through the list in reverse order using a For loop we gain the ability to remove unwanted dates with impunity, so that is the route to take.

Next, we grab the first date in the (possibly updated) list as we will use that to set the current date in a later step, and then convert the list of dates into a set of ranges. To do this we need a new method:

public IEnumerable<SelectionRange> GetRanges(IEnumerable<DateTime> dates)
{
    var ranges = new List<SelectionRange>();
    SelectionRange currentRange = null;

    // this presumes a list of dates ordered by day, if not then the list will need sorting first
    var dateTimes = dates as DateTime[] ?? dates.ToArray();
    for (int i = 0; i < dateTimes.Length; ++i)
    {
        var currentDate = dateTimes[i];

        if (i == 0 || dateTimes[i - 1] != currentDate.AddDays(-1))
        {
            // it's either the first date or the current date isn't consecutive to the previous so a new range is needed
            currentRange = new SelectionRange
            {
                Start = currentDate
            };

            ranges.Add(currentRange);
        }

        if (currentRange != null)
        {
            currentRange.End = (currentDate);
        }
    }

    return ranges;
}

Hopefully this is pretty self-explanatory, we just iterate the dates adding to one or more ranges as we go and then return the ranges.

Back in our calling method we now iterate the returned ranges and add them to the calendar:

SQL

// Add in the returned ranges
foreach (var selectionRange in ranges)
{
    _selectionRanges.Add(selectionRange);
}

Now all that remains is to set the current date and call EndUpdate, and we are all done.

I hope that this all proves useful to someone, and I will report back if I find any more issues that need to be addressed.

Chris Bray

modified 9-Nov-14 16:18pm.

Hi Chris,

thanks for finding the bug, much appreciated.

Fixed it in the new VS 2012/2013 demo solution files.

Bye,

Thomas.

Pleased to have been of help. I am enjoying working with your code and extending it to make it fit my needs, and would be happy to contribute my changes and additions back to the project if you think that they are appropriate. For example, in addition to the changes I posted yesterday I have added the following features as of today:

• The ability to turn off the Today indicator when required
• The ability to turn off date selection (for situations where you want to display information only) by adding a None member to the MonthCalendarSelectionMode enum and handling that value where appropriate
• The ability to define a Symbol (or text) and Font as part of a BoldedDateCategory so that for example a user could mark off holidays by removing the numbers and replacing with a suitable symbol. It would also be possible to use a character or two characters instead of a symbol if preferred, for example 'H' for holiday or 'V' for vacation... The act of simply setting a Symbol changes the behaviour of the renderer to suit, so no additional properties or markers are required. If no font is supplied then the font of the calendar is used. If neither is provided the day is rendered as normal.

If any of this is of interest do let me know. Thanks again for providing a fantastic control.

modified 10-Nov-14 10:09am.

Hi Chris,

yeah, I find your changes really good and can easily see that others would appreciate that as much as me.

So, if you send me your code, I will provide a download link at the top of the article.
Or you could publish an alternate article to this one - your choice Smile | :)

Regards,

Thomas.

Hi Thomas,

OK, I guess that means that you don't want to modify your project with my contribution which is of course absolutely fine. I will continue to work on my version and let you know when I think it might be ready for a new article.

I have now changed 'Bold' to 'Featured' in order that it makes more sense semantically, and have added keyboard support when in Manual mode. I have other ideas and plans too, so hopefully those will come to fruition in the not too distant future.

I will keep you posted!

I have a field that can have a nullable value, does the control support null date, in which case it will show empty value

A *long* time since I looked at this, but the short answer is no. The control works with DateTime, and selecting individual dates within the available range. If the date is null, there is nothing to select so just ignore it.

On the other hand, if you try to pass a nullable DateTime to the control you should expect an exception.

Chris Bray

I tried to include your project in a new vs2012 empty solution but it have many errors which are hard to find out why. There are more than thousands of errors and may have many different stupid and simple reasons because of different options and settings in visual studio versions and projects.
So please upload another source containing all your vs settings for this project to be compiled.

Hi,

these are quite simple errors - you need to add 3 references to the project containing the source files for the control: System.Windows.Forms, System.Drawing and System.Design

And of course you have to adjust some other small things.

Regardless, I created new VS 2012/2013 demo-solutions and added them to the article.

Bye,

Thomas.

Hi
I am unable to run the application.
it's giving error

Hi,

so what's the error?
What did you try?

Bye,

Thomas.

Culture Aware Month Calendar and DatePicker

Introduction

Background

Class Diagram

Features

Using the Code

Points of Interest

Customization of the MonthControl

Adjusting the MonthCalendar Control

Adjusting the DatePicker Control

Extended Bolded Dates

Usage of Native Digits

Events

History

License

Comments and Discussions