Nullable DateTimePicker

Sample Image - Nullable_DateTimePicker.jpg

Introduction

I had do a research on a DateTimePicker that could enter null value and found a lot of solutions to it. But one major problem with those is that they behave quite different from the standard ones and may have many potential bugs, as a result it took time to test before using in a real application. I just found another simple solution that could solve this problem with a little modification, so it could promise no bugs :-).

Solution

I have overridden the Value property to accept Null value as DateTime.MinValue, while maintaining the validation of MinValue and MaxValue of the standard control. That's all there's to it.

Because it's so simple, there's not much to say about it. Please refer to code for details.

You must Sign In to use this message board.


Per page

Set Nullable DateTimePicker default value [00/00/0000]
tinhleduc

1:27 26 Feb '10

You can set NullFormat to [00/00/0000]

string _NullFormat = "00/00/0000";
public string NullFormat
{
        get { return this._NullFormat; }
        set { this._NullFormat = value; }
}
protected override void OnKeyDown(KeyEventArgs e)
{
	base.OnKeyDown (e);

        if (e.KeyCode == Keys.Delete)
        {
                this.Value = DateTime.MinValue;
                this.ValueNullable = null;
                //Backup CustomFormat
                if (this.CustomFormat != _NullFormat) this._OldCustomFormat = this.CustomFormat;
                this.CustomFormat = _NullFormat;
        }
        else
        {
                this.CustomFormat = this._OldCustomFormat; //Restore
        }
}
protected override void OnValueChanged(EventArgs e)
{
      base.OnValueChanged(e);
      this.ValueNullable = base.Value;
}

http://www.sendspace.com/file/8qtjdj[Download Sample]

tinhleduc@gmail.com

Update
Romain TAILLANDIER

23:37 21 Sep '09

Hello,

I use your code, because it is elegant, simple and efficient, as Phil Raevsky said.
I have used all remarks from the forum and found some new upgrades.

 public class NullableDateTimePicker : System.Windows.Forms.DateTimePicker
{
    DateTimePickerFormat _Format;
    string _CustomFormat;
    private DateTime? _ValueNullable;

    public NullableDateTimePicker()
        : base()
    {
        _Format = base.Format;
        _CustomFormat = base.CustomFormat;
    }

    // overrides of this two property 
    // because in case of modifying Format or CustomFormat at runtime, saved values become obsolete, and could be restored

    public new DateTimePickerFormat Format
    {
        get { return base.Format; }
        set { this._Format = value; base.Format = value; }
    }
    public new string CustomFormat
    {
       get { return base.CustomFormat; }
       set { this._CustomFormat = value; base.CustomFormat = value; }
    }

    // using the nullable Datetime from alc_aardvark
    public DateTime? ValueNullable
    {
        get 
        { 
            // May be have to test this
            // if(_ValueNullable.HasValue && (_ValueNullable.Value <= this.MinDate || _ValueNullable.Value >= this.MaxDate))
            //     // do something
            return _ValueNullable; 
        }
        set
        {
            _ValueNullable = value;
            // Be carefull of limits, that cause ArgumentOutOfRangeExceptions
            // Limits are not from DateTime, but from this !
            // In this case Over range values, i do as if value was null (for printing)
            if(!_ValueNullable.HasValue || value <= this.MinDate || value >= this.MaxDate) 
            {
                // show nothing in datetime picker
                base.Format = DateTimePickerFormat.Custom;
                base.CustomFormat = " ";
                base.OnValueChanged(EventArgs.Empty);
            }
            else
            {
                // restore printing.
                base.Format = _Format;
                base.CustomFormat = _CustomFormat;
                base.Value = _ValueNullable.Value;
            }
        }
    }

    // Override this property to be sure ValueNullable is used.
    public new DateTime Value
    {
        get
        {
            if(!_ValueNullable.HasValue) // if( value == null)
               return this.MinDate; // or DateTime.MinValue
            return ValueNullable.Value;
        }
        set
        {
            this.ValueNullable = value;
        }
    }

    protected override void OnKeyDown(KeyEventArgs e) 
    { 
        ... //same as original version
    }
    protected override void OnCloseUp(EventArgs eventargs)
    { 
        ... //same as original version
    }
       
}

Hope that could help.

Romain TAILLANDIER
www.romaintaillandier.blogspot.com
romaintaillandier.free.fr
www.maintag.fr

This is a very insightful approach to the problem
Phil Raevsky

17:01 28 Aug '09

Simple, elegant, and almost perfect
Sign In·View Thread·PermaLink

This one dispaly pink if null date (VB.NET)
Larry Rouse

12:32 28 Aug '09

Imports System
Imports System.Windows.Forms
Namespace Controls
Public Class DateTimePicker
Inherits System.Windows.Forms.DateTimePicker
Private bIsNull As Boolean = False
Private mBackColor As Color = SystemColors.Window
Public Sub New()
MyBase.New()
End Sub
Public Shadows Property Value() As DateTime
Get
If bIsNull Then
Return DateTime.MinValue
Else
Return MyBase.Value
End If
End Get
Set(ByVal value As DateTime)
If value = DateTime.MinValue Or value.Date = "01/01/1905" Or value.Date = "01/01/1900" Then
If bIsNull = False Then bIsNull = True
MakePinkFormat()
Else
MakeWhiteFormat()
bIsNull = False
MyBase.Value = value
End If
End Set
End Property
' Protected Overloads Overrides Sub OnCloseUp(ByVal eventargs As EventArgs)
Protected Overrides Sub OnCloseUp(ByVal eventargs As EventArgs)

If Control.MouseButtons = MouseButtons.None Or Control.MouseButtons = Windows.Forms.MouseButtons.Left Then
Me.Value = MyBase.Value
End If
MyBase.OnCloseUp(eventargs)
End Sub
Protected Overloads Overrides Sub OnKeyDown(ByVal e As KeyEventArgs)
MyBase.OnKeyDown(e)

If e.KeyCode = Keys.Delete Then
Me.Value = DateTime.MinValue
MyBase.Value = "01/01/1905"
End If
End Sub
Private Sub MakePinkFormat()
Me.Format = DateTimePickerFormat.[Custom]
Me.BackColor = Color.Pink
Me.CustomFormat = " "
MyBase.Value = "01/01/1905"
End Sub
Private Sub MakeWhiteFormat()
Me.Format = DateTimePickerFormat.Short
Me.BackColor = Color.White
Me.CustomFormat = Nothing
End Sub
'The BackColor property we will be calling
Public Overrides Property BackColor() As Color
Get
Return mBackColor
End Get
Set(ByVal Value As Color)
mBackColor = Value
'After the BackColor has been set, Invalidate the control
'This will force it to be redrawn
'Me.Invalidate()
End Set
End Property
'WndProc fires durring the painting of the control
Protected Overrides Sub WndProc(ByRef m As Message)
'Check to see if message being send is WM_ERASEBKGND.
'The hex value of this message is &H14.
'This message is sent when the background of the
'object needs to be erased. In our case though, instead of
'erasing it, we will paint a rectangle over it
If m.Msg = CInt(&H14) Then ' WM_ERASEBKGND
Dim g As Graphics = Graphics.FromHdc(m.WParam)
g.FillRectangle(New SolidBrush(mBackColor), ClientRectangle)
g.Dispose()
Return
End If
MyBase.WndProc(m)
End Sub
Private Sub DateTimePicker_EnabledChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.EnabledChanged
Me.CalendarForeColor = Color.Black
End Sub
End Class
End Namespace

This one works! (VB 2008) [modified]
Jeromeyers

13:55 10 Feb '09

This is an edit because I realized, like the previous poster, than you can simply shadow the Value property of the base DateTimePicker to allow Nullable Dates. That means that it works exactly like you would want/expect it to, in databinding situations and everything.

Public Class NullableDateTimeControl
    Inherits System.Windows.Forms.DateTimePicker

    Private oldFormat As DateTimePickerFormat = DateTimePickerFormat.Short
    Private oldCustomFormat As String = Nothing
    Private _IsNull As Boolean = False


    Public Sub New()
        MyBase.New()
    End Sub


    ''' <summary>
    ''' The Date Value of the control (is Nullable, can be set to Nothing).
    ''' </summary>
    ''' <value></value>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shadows Property Value() As Date?
        Get

            If Me._IsNull Then

                Return Nothing

            Else

                Return MyBase.Value

            End If

        End Get
        Set(ByVal newValue As Date?)

            If Not newValue.HasValue Then

                If Not Me._IsNull Then

                    Me.oldFormat = Me.Format
                    Me.oldCustomFormat = Me.CustomFormat
                    Me._IsNull = True

                End If

                Me.Format = DateTimePickerFormat.Custom
                Me.CustomFormat = " "

            Else

                If Me._IsNull Then

                    Me.Format = Me.oldFormat
                    Me.CustomFormat = Me.oldCustomFormat
                    Me._IsNull = False

                End If

                MyBase.Value = newValue.Value

            End If

        End Set
    End Property


    ''' <summary>
    ''' Allows the user to select a new date if the control is already null.
    ''' </summary>
    ''' <param name="eventargs"></param>
    ''' <remarks></remarks>
    Protected Overrides Sub OnCloseUp(ByVal eventargs As System.EventArgs)

        If Control.MouseButtons = Windows.Forms.MouseButtons.None Then

            If Me._IsNull Then

                Me.Format = Me.oldFormat
                Me.CustomFormat = Me.oldCustomFormat
                Me._IsNull = False

            End If

        End If

        MyBase.OnCloseUp(eventargs)

    End Sub


    ''' <summary>
    ''' Overrides the base class implementation to allow the user to create a Null value by pressing the Delete key.
    ''' </summary>
    ''' <param name="e"></param>
    ''' <remarks></remarks>
    Protected Overrides Sub OnKeyUp(ByVal e As System.Windows.Forms.KeyEventArgs)
        MyBase.OnKeyUp(e)

        If e.KeyCode = Keys.Delete Then

            Me.Value = DateTime.MinValue

        End If

    End Sub


End Class

modified on Wednesday, February 11, 2009 10:51 AM

Re: This one works! (VB 2008)
EMYNA

13:40 28 Oct '09

Hi, i wanna know if this code can be used in visual studio 2008 (visual basic) or i need to make some changes to use them.
Sign In·View Thread·PermaLink

Use the Nullable Datetime for a more updated solution.
chstngs

6:39 7 Oct '08

This way you can actually have a null value for the control.

public new DateTime ? Value
{
get
{
if (bIsNull)
return null;
else
return base.Value;
}
set
{
if (value == null)
{
if (bIsNull == false)
{
oldFormat = this.Format;
oldCustomFormat = this.CustomFormat;
bIsNull = true;
}

this.Format = DateTimePickerFormat.Custom;
this.CustomFormat = " ";
}
else
{
if (bIsNull)
{
this.Format = oldFormat;
this.CustomFormat = oldCustomFormat;
bIsNull = false;
}
base.Value = value.Value;
}
}
}

protected override void OnCloseUp(EventArgs eventargs)
{
if (Control.MouseButtons == MouseButtons.None)
{
if (bIsNull)
{
this.Format = oldFormat;
this.CustomFormat = oldCustomFormat;
bIsNull = false;
}
}
base.OnCloseUp (eventargs);
}

protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown (e);

if (e.KeyCode == Keys.Delete)
this.Value = null;
}

It's really great! Thank you very much!!
wxpwu

3:48 15 Jun '08


Sign In·View Thread·PermaLink	5.00/5

Small correction
Maxxx333

2:32 16 Nov '06

When used out-of-the-box, the user must use the mouse to enter a date once the value has been set to DateTime.MinValue.

Change the KeyUp override as follows:

protected override void OnKeyUp(KeyEventArgs e)
{
base.OnKeyUp(e);

if (e.KeyCode == Keys.Delete)
this.Value = DateTime.MinValue;

else if (this.Value == DateTime.MinValue
&& (e.KeyCode == Keys.Space || Char.IsNumber((char)e.KeyValue)
|| e.KeyCode == Keys.Up || e.KeyCode == Keys.Down
|| e.KeyCode == Keys.Right || e.KeyCode == Keys.Left))
this.Value = DateTime.Today;
}

This allows the user to get the "normal" date in the box after pressing a space, any arrow key, or any number.

Comments?

Re: Small correction - an enhancement to that correction
ccbt

20:27 9 Sep '09

While this allowed the control to go back to edit mode after it was set to null, I didn't like the way it would go back to Today's date. The reason being... Today is 09/09/09. Well, lets say I want to go into that field and enter in an April date, I will hit 4 and it will display 09/09/2009. I will have to hit 4 again to enter the April date.

I tried moving the base.OnKeyUp(e) call after the code to set today's date so it would persist the 4 into the control and that didn't work. Then I tried moving the code to the OnKeyDown event handler. That didn't work either. So I found away around it be using some date manipulation:

        protected override void OnKeyDown(KeyEventArgs e)
        {


            if (e.KeyCode == Keys.Delete)
            {
                this.Value = null;
            }
            else if ((this.Value == DateTime.MinValue || this.Value == null)
                && (e.KeyCode == Keys.Space || Char.IsNumber((char)e.KeyValue)
                || e.KeyCode == Keys.Up || e.KeyCode == Keys.Down
                || e.KeyCode == Keys.Right || e.KeyCode == Keys.Left))
            {
                DateTime newDate = DateTime.Today;
                if (Char.IsNumber((char)e.KeyValue))
                {
                    newDate = DateTime.Parse(string.Format("{0}/{1}/{2}", (char)e.KeyValue, DateTime.Today.Day, DateTime.Today.Year));
                }
                this.Value = newDate;
                
            }
            base.OnKeyDown(e);

        }

NOTE: I have also included a check for this.Value == null because I also altered the class to use a Nullable(DateTime). Also, this is in the OnKeyDown event. I moved this from the previously suggested OnKeyUp. I think it will work either way, though.

Re: Small correction - an enhancement to that correction BugFixing =) [modified]
Leonunicorn

2:45 4 Dec '09

Hi there,

I have fixed some bugs and...

extended it to...

- use two digits
- international support
- using numpad

bugs fixed:
- using Zero "0" numeric exception
- always got april
- can't use two digits
- null value exception

       protected override void OnKeyDown(KeyEventArgs e)
        {
            base.OnKeyDown(e);
            if (e.KeyCode == Keys.Delete)
            {
                this.Value = DateTime.MinValue;     //<--- null does not work, so there is the origin value
            }
            else if ((this.Value == DateTime.MinValue || this.Value == null)
                && (e.KeyCode == Keys.Space || (Char.IsNumber((char)e.KeyValue) && e.KeyValue != 48)    //<-- "0" correction
                || e.KeyCode == Keys.Up || e.KeyCode == Keys.Down || e.KeyCode == Keys.Right
                || e.KeyCode == Keys.Left
                || (e.KeyValue >= 97 && e.KeyValue <= 105) //<-- NumPad1 - NumPad9
                ))
            {

                int typedDigit = 1;
                if (e.KeyValue >= 97 && e.KeyValue <= 105)
                {//<-- NumPad1 - NumPad9 must be calculated to numeric KeyValues
                    typedDigit = int.Parse(((char)e.KeyValue - 46).ToString());
                }
                else
                {
                    typedDigit = int.Parse(((char)e.KeyValue).ToString());
                }
                

                DateTime newDate = DateTime.Today;
                if (Char.IsNumber((char)e.KeyValue))
                {
                    newDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, typedDigit);    //<-- this allows international format of the datetimepicker
                } 
                this.Value = newDate;
                SendKeys.Send(typedDigit.ToString()); //<-- this allows typing two digits at once without typing it again as example "12" or "27"
            }
            
            
        }

modified on Friday, December 4, 2009 9:02 AM

Re: Small correction - an enhancement to that correction BugFixing x 2 [modified]
kipotlov

7:14 11 Dec '09

I got an exception on this line when i pressed space and the value is null :

typedDigit = int.Parse(((char)e.KeyValue).ToString());
I fixed it like this :

        protected override void OnKeyDown(KeyEventArgs e)
        {
            base.OnKeyDown(e);
            if (e.KeyCode == Keys.Delete)
            {
                this.Value = DateTime.MinValue;
            }
            else if (this.Value == DateTime.MinValue || this.Value == null)

            {
                if (e.KeyCode == Keys.Space || e.KeyCode == Keys.Up || e.KeyCode == Keys.Down 
                    || e.KeyCode == Keys.Right || e.KeyCode == Keys.Left)                 
                {
                    this.Value = DateTime.Today;
                }
                else if ((Char.IsNumber((char)e.KeyValue) && e.KeyValue != 48) //<-- "0" correction
                    || (e.KeyValue >= 97 && e.KeyValue <= 105)) //<-- NumPad1 - NumPad9       
                {
                    int typedDigit = 1;
                    if (e.KeyValue >= 97 && e.KeyValue <= 105)    //<-- NumPad1 - NumPad9 must be calculated to numeric KeyValues        
                    {
                        typedDigit = int.Parse(((char)(e.KeyValue - 48)).ToString());
                    }
                    else //if (Char.IsNumber((char)e.KeyValue))
                    {
                        typedDigit = int.Parse(((char)e.KeyValue).ToString());
                    }

                    this.Value = new DateTime(DateTime.Today.Year, DateTime.Today.Month, typedDigit); //<-- this allows international format of the datetimepicker

                    SendKeys.Send(typedDigit.ToString()); //<-- this allows typing two digits at once without typing it again as example "12" or "27"         
                }
            }
        }

modified on Friday, December 11, 2009 1:29 PM

Re: Small correction - an enhancement to that correction BugFixing x 2
Leonunicorn

5:57 15 Dec '09

thanks =)

I have fixed an another issue too...

When you enter a date by keyboard and a MaxDate or MinDate is set, it will throw an exception.

I change the code again...

       public new DateTime Value
        {
            get
            {
                if (bIsNull)
                    return DateTime.MinValue;
                else
                    return base.Value;
            }
            set
            {
                if (value == DateTime.MinValue)
                {
                    if (bIsNull == false)
                    {
                        oldFormat = this.Format;
                        oldCustomFormat = this.CustomFormat;
                        bIsNull = true;
                    }

                    this.Format = DateTimePickerFormat.Custom;
                    this.CustomFormat = " ";
                }
                else
                {
                    if (bIsNull)
                    {
                        this.Format = oldFormat;
                        this.CustomFormat = oldCustomFormat;
                        bIsNull = false;
                    }
//MinMaxDate fix
                    if (value < this.MaxDate && value > this.MinDate)
                    {
                        base.Value = value;
                    }
                    else if (value > this.MaxDate)
                    {
                        value = this.MaxDate;
                    }
                    else if (value < this.MinDate)
                    {
                        value = this.MinDate;
                    }
                }
            }
        }

Re: Small correction - an enhancement to that correction BugFixing x 2
Leonunicorn

4:42 4 Jan '10

I am back *smile*

Found a bug, when changing the DateTime Value to nothing (DateTime.MinValue) the ValueChanged Event will not be raised, so I put in an Eventraiser...

        public new DateTime Value
        {
            get
            {
                if (bIsNull)
                    return DateTime.MinValue;
                else
                    return base.Value;
            }
            set
            {
                if (value == DateTime.MinValue)
                {
                    if (bIsNull == false)
                    {
                        oldFormat = this.Format;
                        oldCustomFormat = this.CustomFormat;
                        bIsNull = true;
                    }

                    this.Format = DateTimePickerFormat.Custom;
                    this.CustomFormat = " ";
                    base.OnValueChanged(new EventArgs());   //Fix to raise a valuechange event when setting the DateTime Value to DateTime.MinValue (faked null)
                }
                else
                {
                    if (bIsNull)
                    {
                        this.Format = oldFormat;
                        this.CustomFormat = oldCustomFormat;
                        bIsNull = false;
                    }

                    //MinMaxDate fix
                    if (value < this.MaxDate && value > this.MinDate)
                    {
                        base.Value = value;
                    }
                    else if (value > this.MaxDate)
                    {
                        value = this.MaxDate;
                    }
                    else if (value < this.MinDate)
                    {
                        value = this.MinDate;
                    }
                }
            }
        }

Null Button?
Kysonel

10:48 28 Mar '06

I found this pretty usefull, but do you know a way to place a button in the calendar to place the null value? like the "today" button there is in the lower left corner... I'm using vb.net :P just so you know. thanks!
Sign In·View Thread·PermaLink	2.00/5

How to use?
strent00

6:54 21 Dec '05

The sample project doesn't work for me -- pressing delete does nothing. What gives? How do I use this control in a project? Relative performance is no substitute for absolute achievement.
Sign In·View Thread·PermaLink	1.45/5

Cool!
Super Lloyd

17:36 19 Dec '05

I like it Actually change Value so it is a "DateTime?", much nicer And also I used both Delete & Backspace for having an empty date
Sign In·View Thread·PermaLink

Clicking on current date in dropdown doesn't show datetime
jfk80@wp.pl

3:38 15 Mar '05

When NullableDateTimePicker (NDTP) state is null and it doesn't show value, click on the dropdown and select current value at the bottom of the dropdown, near red circle mark. This should change the NDTP state to not-null and show current DateTime. But NDTP checks if user selected value in dropdown by checking that no mouse button is pressed (in OnCloseUp), which is true only if a calendar was clicked, but not if bottom mark was clicked.
IMO, there is solution for this is not to rely on mouse button state in OnCloseUp. Instead override OnValueChanged and set a flag, then use it in OnCloseUp.
Thus:


		protected override void OnCloseUp(EventArgs eventargs) {
			if (Control.MouseButtons == MouseButtons.None || fHasValueChanged) {
				if (fIsNull) {
					this.Format = fOldFormat;
					this.CustomFormat = fOldCustomFormat;
					fIsNull = false;
				}
				fHasValueChanged = false;
			}
			base.OnCloseUp(eventargs);
		}
		protected override void OnKeyUp(KeyEventArgs e) {
			base.OnKeyUp(e);
			if (e.KeyCode == Keys.Delete) {
				this.Value = DateTime.MinValue;
				this.fHasValueChanged = false;
			}
		}
		protected override void OnValueChanged(EventArgs eventargs) {
			fHasValueChanged = true;
			base.OnValueChanged(eventargs);
		}

Resetting to false in OnKeyUp has to be done, because user can change value by hand, not by dropdown. In such case the flag remains true which could cause problems if user presses delete on NDTP and then pressed and depressed dropdown arrow (without changing value). If flag is not reset when she pressed delete, than suddenly NDTP would show value.

bind data to date time picker
ccloon

23:11 20 Feb '05

hi all, i am using sql server and vb.net 2002 to develop my project. the problem i face now is when i bind the null value (datatype = datetime) into the date time picker control, it show an error please help, i need the code in vb.net loon Have a nice day
Sign In·View Thread·PermaLink	1.00/5

Re: bind data to date time picker
Claudio Grazioli

11:36 28 Mar '05

ccloon wrote: i am using sql server and vb.net 2002 to develop my project.
the problem i face now is when i bind the null value (datatype = datetime) into the date time picker control, it show an error
Have a look at this version of a nullable date time picker.
http://www.omnitalented.com/Blog/PermaLink,guid,9ee757fe-a3e8-46f7-ad04-ef7070934dc8.aspx It can handle "real" null values as you get them from databases.

You request it in VB. I'm sorry, it's in C#. But it's simple. I'm sure you manage to translate it.

Claudio Grazioli
http://www.grazioli.ch

Re: bind data to date time picker
Claudio Grazioli

23:45 24 May '05

As I already wrote you, this nullable DateTimePicker[^] can handle null values. I created a VB.NET version of this control now and you can get it here: nullable DateTimePicker for VB.NET[^] Claudio Claudio's Website Hommingberger Gepardenforelle
Sign In·View Thread·PermaLink

Re: bind data to date time picker
alc_aardvark

7:07 14 May '08

I tried this version and binding a nullable datetime does not work, as it leaves the last valid date from a previous bind. Here is a different version that seems to work better. NB. 5 minutes of testing only. Just dataBind to the ValueNullable property as opposed to the Value property if you have a Nullable DateTime. This should work as normal if you have a normal DateTime (bind to Value).

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;

namespace Invisage.PinkFloyd.Library.Controls
{
public class DateTimePickerNullable : System.Windows.Forms.DateTimePicker
{
DateTimePickerFormat mOriginaldateTimePickerFormat;
private DateTime? mValueNullable;

public DateTimePickerNullable()
: base()
{
mOriginaldateTimePickerFormat = base.Format;
}

[Category("PinkFloyd")]
[Description("Nullable DateTime")]
[Bindable(true)]
public DateTime? ValueNullable
{
get { return mValueNullable; }
set
{
mValueNullable = value;

if (!mValueNullable.HasValue)
{
this.Format = DateTimePickerFormat.Custom;
this.CustomFormat = " ";
}
else
{
this.Format = mOriginaldateTimePickerFormat;
base.Value = mValueNullable.Value;
}
}
}

protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown (e);

if (e.KeyCode == Keys.Delete)
{
ValueNullable = null;
}
}
}
}

Re: bind data to date time picker
Roonda

20:13 6 Apr '09

Have you tried pressing the Delete button when the ValueNullable it is bound? I think you'll find it doesn't work.
Sign In·View Thread·PermaLink

Display blank space when NULL
SupaHoopsa

5:56 9 Feb '05

Your control could possibly be what I am looking for. I want to be able to display either a blank space or a customer phrase (such as "No Date Entered" when the date is NULL. Can your control handle this?
Sign In·View Thread·PermaLink	2.00/5

Re: Display blank space when NULL
Claudio Grazioli

23:16 19 Apr '05

Have a look at this other DateTimePickers, they support that: NullableDateTimePicker with DateTime.MinDate/DateTime.MaxDate[^] as null value. NullableDateTimePicker with null[^] as null value. Claudio Claudio's Website Hommingberger Gepardenforelle
Sign In·View Thread·PermaLink	1.63/5