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Introduction

Similar controls:

1. System.Windows.Forms.DateTimePicker
2. gTimePicker

How this control differ:

Features comparison:

	DateTimePicker	gTimePicker	TimeEdit
Value Update	On Mask complete On Lost focus On validated	On Lost focus On validated	Immediately after key press
Text and Value is always the same	No	No	Yes
Null Value Support	No	Yes	Yes
could have time only value: like 0001/01/01 01:00	No	Yes	Yes
Has a dropdown clock	No	Yes	In the next version
It is not needed to use : or arrows when entering time	No	No	Yes

Value after key press:

	DateTimePicker	gTimePicker	TimeEdit
Example displayed Text	00:00	00:00	00:00
Displayed text after pressing [6] Key	6:00	60:00	06:00
Value after pressing [6] Key	00:00 + current date	00:00	06:00
Value after lost focus	06:00	06:00	06:00

Why I Decided to Create It

I need a control that has the following features:

1. Value property can be set to time only value such as 00:00 (0001/01/01 00:00) witch is the minimum value for DateTime Type
2. Value property can be DBNull.Value and this is useful for database binding
3. Edit time that always it value reflect the displayed text
4. Simple time entering by minimum typing
5. Could the increase or decrease its value by mouse weal moving or by arrows pressing

Value Related Property of this Control

1. Value                 (Object):                     DBNull   or WorkingDayDate and Time.
2. NullableDateTime  (Nullable(of DateTime)): Nothing or WorkingDayDate and Time.
3. NullableTime        (Nullable(of DateTime)): Nothing or Time.

What This Application Does and Why it is Useful

You could include this control in your application to get the following features:

1. Allows your application user to enter a time in 24 hour or 12 hour mode
2. Protects your application user from entering invalid time
3. If your application check the value of this control it will always return the right value even before the control lost focus and this is useful to get the value changing as user typing.
4. You could assigned TimeEdit control with a WorkingDayDateControl to return a date and time in a single property
5. It is a simple control and it is inherits from a TextBox and easy to understand and could be devolved to another more complex control
6. It is an alternative and more useable than DateTimePicker

What Problem is Solved

1. When user changes the text of TimeEdit control, its value changes immediately even if it does not lose focus.
2. TimeEdit control does not have a MinValue so it could point to time only value.
3. It has a WorkingDayEndTime and WorkingDayDate property that is useful when used in appointment arrangement in a working day that continues after midnight
4. It could be assigned to WorkingDayDateControl to get the date part form it and return the date and time in a single Value property

Globalization

This control will act the same even if your local culture is differ than en-US.
It always use AM PM and : even if your local culture is use others

What the Next Step

1. Add a drop down button to display a clock to select time.
2. Building an appointment grid to arrange appointments that could be continue after mid night without break sorting (00:00 will located after 23:59 when sorting by time

Using the Code

1. You could TimeEdit control in your Windows application to mentioned time
2. If you build a user control could use TimeConverter and DateConverter for your control property.

The Demo application:

The demo application comparing between DateTimePicker and TimeEdit control. Ther is 2 TimeEdit control the first one has WorkingDayEndTime property set to 00:00 and the second TimeEdit control its WorkingDayEndTime is set to 02:00
When typing in any TimeEdit control or in the DateTimePicker control the value of the control is shown
the date of the second TimeEdit control is set to 0001/01/02 (yyyy/MM/dd) if the time typed is less that WorkingDayEndTime
and this is useful when sorting time in an appointments arrangements

Points of Interest

How to keep Value and Text the same:

To do so we don't store the value in a separate variable we use the displayed text to get the value. and when user is set the value programmatically this control will study the value:

1. If new value is numeric it will considered as Hour; 6.5 will be converted to 06:30
2. If new value is DateTime then the WorkingDayDate property will be set to the new value date and the NullabeTime property will be set to time part of the new value
3. if new value is empty string then value will be DBNull
4. if new value is string that contains time then the value will return its value

    Public Overridable Property Value As Object
        Get
            Try
                If String.IsNullOrEmpty(MyBase.Text) Then
                    Return DBNull.Value
                Else
                    Return Me.NullableDateAndTime.Value
                End If
            Catch ex As Exception
                ErrMsg(ex)
                Return DBNull.Value
            End Try
        End Get
        Set(ByVal NewValue As Object)
            Try
                If IsNumeric(NewValue) Then
                    'Nothing = 00:00
                    'not include date
                    Me.NullableTime = (New Date).AddHours(CDbl(NewValue))
                ElseIf IsDate(NewValue) Then
                    'Nothing = 00:00
                    'include date
                    Me.NullableDateAndTime = CDate(NewValue)
                ElseIf IsDBNull(NewValue) OrElse NewValue Is Nothing Then
                    Me.Text = ""
                ElseIf GetType(TimeSpan).IsAssignableFrom(NewValue.GetType) Then
                    'not include date
                    Me.NullableTime = New Date(CType(NewValue, TimeSpan).Ticks)
                ElseIf GetType(String).IsAssignableFrom(NewValue.GetType) Then
                    If String.IsNullOrEmpty(CStr(NewValue)) Then
                        Me.Text = ""
                    Else
                        'don't include date
                        Me.NullableTime = ToDateTime(CStr(NewValue))
                    End If
                Else
                    Me.Text = ""
                End If
            Catch ex As Exception
                ErrMsg(ex)
            End Try
        End Set
    End Property

Validate Time Input and Protecting User from Entering Invalid Time

1. Overrides Sub OnKeyPress
2. If user press a key in an empty TimeEdit control then it will automatically assign with default value
3. Build sText string that echo the user input result  

   Dim sText = Me.Text
   Mid(sText, Me.SelectionStart + 1, 1) = e.KeyChar 'Replace the 2d char

4. Test if the resulting text is valid Time using Regular Expressions taking "^(?<Hour>([0-1]\d|2[0-3])):(?<Minute>[0-5]\d)$" for 24 hour mode and "^(?<Hour>(0?[1-9]|1[0-2])):(?<Minute>[0-5]\d) (?<AMPM>(A|P)M)$" for 12 hour mode
   * This Regular Expressions contains three groups Hour, Minute and AMPM
   * Each group has its rule example Hour in 12 hour mode is 0 followed by any digest or 1 followed by 0-2  
5. If not match then study where the editing char in hours or in minutes and study its possible fixing as follwing code:  

       Private Sub OnHourKeyPress(ByRef e As KeyPressEventArgs)
           Try
               Dim Do1 = False
               Select Case SelectionStart
                   Case 0 'SelectionStart = 0
                       Select Case e.KeyChar
                           Case "3"c To "9"c 'not allowed to be first char
                               Do1 = True
                           Case "2"c 'not allowed to be first char in 12 Hr mode
                               If Not _Hr24 Then
                                   Do1 = True
                               Else
                                   'in 24 hr mode if the next char is > 3 then replace it with 3
                                   If Me.Text()(1) > "3"c Then
                                       Mid(Me.Text, 2, 1) = "3"
                                   End If
                               End If
                           Case "1"c
                               If Not _Hr24 Then
                                   'in 12 hr mode if the next char is > 2 then replace it with 2
                                   If Me.Text()(1) > "2"c Then
                                       Mid(Me.Text, 2, 1) = "2"
                                   End If
                               End If
                       End Select
                   Case 1 'SelectionStart = 1
                       Select Case MyBase.Text(0)
                           Case Is > "2"c
                               'in 12 hr mode not allowed to be in 2d char
                               If Not Hr24 Then
                                   Do1 = True
                               End If                            
                           Case "2"c
                               If Me.Hr24 Then                                
                                   Select Case e.KeyChar
                                       Case "4"c To "9"c
                                           'in 24 hr mode not allowed to be in 2d char
                                           Do1 = True
                                   End Select
                               Else
                                   Do1 = True
                               End If
                           Case "1"c
                               If Not _Hr24 Then
                                   Select Case e.KeyChar
                                       Case "3"c To "9"c
                                           Do1 = True
                                   End Select
                               End If
                       End Select 'MyBase.Text(0)
               End Select
               If Do1 Then
                   Me.Text = "0" & Me.Text.Substring(1)
                   SelectionStart = 1
                   SelectionLength = 1
               End If
               OnTimeKeyPress(e)
           Catch ex As Exception
               ErrMsg(ex)
           End Try
       End Sub

TimeEdit control Inherits TextBox but it removes some properties by:

1. Adding Designer attribute:

   <ToolboxItem(True), Designer(GetType(TimeEditDesigner)), _
   DefaultBindingProperty("Value")> _
   Public Class TimeEdit
       Inherits TextBox
   
       '....More Code....
   
       <DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), _
       Browsable(False), Obsolete("", True)> _
       Public Shadows Lines, Multiline, AutoCompleteMode, _
       AutoCompleteSource, AutoCompleteCustomSource, WordWrap, _
       PasswordChar, UseSystemPasswordChar As DBNull
   End Class

2. Building TimeEditDesigner class:

   Imports System.Windows.Forms.Design
   Imports System.ComponentModel
   
   Public Class TimeEditDesigner
       Inherits ControlDesigner
   
       Protected Overrides Sub PreFilterProperties(ByVal properties As IDictionary)
           Try
               properties.Remove("PasswordChar")
               properties.Remove("UseSystemPasswordChar")
               properties.Remove("Text")
               properties.Remove("Lines")
               properties.Remove("Multiline")
               properties.Remove("AutoCompleteMode")
               properties.Remove("AutoCompleteSource")
               properties.Remove("AutoCompleteCustomSource")
               properties.Remove("WordWrap")
   
               MyBase.PreFilterProperties(properties)
   
           Catch ex As Exception
               ErrMsg(ex)
           End Try
       End Sub
   
       Public Overrides ReadOnly Property ActionLists As _
       System.ComponentModel.Design.DesignerActionListCollection
           Get
               Return Nothing
           End Get
       End Property
   
       Public Overrides ReadOnly Property Verbs As _
       System.ComponentModel.Design.DesignerVerbCollection
           Get
               Return Nothing
           End Get
       End Property
   End Class

How this application handle run time errors:

Every procedure has the following diagram

Private Sub OnHourKeyPress(ByRef e As KeyPressEventArgs) 'procedure start
    Try
    
    '.... procedure code
  	Catch ex As Exception
		ErrMsg(ex)
    End Try
End Sub 'procedure end

A module that containing ErrMsg procedure is added to the project to document every run time error happened in a file located in "C:\Temp"

The error is printed to that file using as follows:

FileOpen(iFile, sLogFileName, OpenMode.Append, OpenAccess.Write)
Print(iFile, vbNewLine & vbNewLine & "Date: " _
          & Now.ToString("yyyy/MM/dd HH:mm:ss") & vbNewLine)
Print(iFile, sMsg)
FileClose(iFile)

History

• Initial version